Equation for determining your Terminal Length

[KittyMeowMeow]

Hi ladies! I made an equation to determine (approximately) your terminal length.

WHAT IS TERMINAL LENGTH?

It's the theoretical maximum length your hair will attain given no breakage or trims. It's actually better thought of as terminal time, which is the length of time that each strand grows until it is shed. By multiplying your growth rate by your terminal time, we get your terminal length. Each hair is on it's own schedule, and is continually growing, so this is why you don't suddenly go bald or your hair doesn't suddenly stop growing. It's always growing, but at terminal length, it just won't appear to get longer.

THE EQUATION:

yearly shed rate = avg # hairs shed daily x 365 days
terminal time = # hairs on head / yearly shed rate
terminal length = terminal time x yearly growth rate

Example: If you shed 100 hairs per day (maximum considered normal. NOTE: most people shed much less than this) and grow 1/2"/month (average growth rate), your TL is 16.4":

100 hairs shed daily x 365 days = 36,500 hairs shed per year
100,000 hairs on the head / 36,500 = 2.74 years
2.74 x 6 inches = 16.4 inches

ABOUT THE VARIABLES:

# of hairs on head: this is approximate. I've seen 100,000 as an average. Also, someone calculated it by hair color: BLONDE - 140,000 strands; BROWN - 110,000 strands; BLACK - 108,000 strands; RED - 90,000 strands

I assume that actually it would be more for fine strands, fewer for course (which actually lines up with these numbers since redheads and many people with black hair such as Indians and Asians tend to have course hair, and many blondes tend to have fine hair, but anyway). I used 100,000 for my equation, but you can play with different numbers to determine a range.

# of hairs shed daily: shedding (with a white bulb on the end), not breakage. If you ever find your shed hairs around the house (aka not while detangling), round up.

yearly growth rate: average is 6" per year, or 1/2" per month.

INCREASING TERMINAL LENGTH

The equation suggests 3 ways to increase terminal length. Any would have to be used continually once at natural terminal length to maintain:

a. increasing the monthly growth rate: if drinking water, taking vitamins, nutritional adjustments and/or growth aids increase growth rate, this would increase terminal length while they're being used.

b. decreasing the number of shed hairs: I've heard garlic (topical and/or supplements) and tea rinses (?) may help. Dunno.

c. increasing the length of the growth phase: I've heard that MSM can help with this. I'm unsure of how much. Multiply the length of increase from MSM (various sources on the internet) in months by the monthly growth rate to determine increases to terminal length.

Of course, few of us are anywhere near our terminal length, and it's about retention. I think most people will have a terminal length far longer than they'd want to grow their hair, which means we don't need to worry about it! Just thought it would be fun to put this out there and see what others thought!

HHG ladies!

 

[Nasdaq_Diva]

Dang you got alot of time on your hands



Nah, seriously..thanks for the calculations. Curious, have you calculated your own? what's your terminal length?

 

[KittyMeowMeow]

Dang you got alot of time on your hands



Nah, seriously..thanks for the calculations. Curious, have you calculated your own? what's your terminal length?

Yeaaaah, procrastinating on other stuff I should be doing, ha ha.

Here's mine:

I normally shed 0 - 2 hairs per day, with about 10-15 daily for a week while the weather is changing (I used 15 to round it up). When I realized I was shedding a very small amount, I thought it meant I might have a long TL and decided to come up with the equation out of curiosity. Based on my NG after my last relaxer (ever!), I grew about 4.5" last year (slower than average, but slow n steady... ).

15 x 365 = 5,475
100,000/5,475 = 18.26 years
18.26 x 4.5 inches = 82.2 inches = 6.85 feet (10.25 if I use 10 for the avg hairs per day)

I got a looong way to go, meaning it's all on me to retain!

 

[SingBrina]

Wow this is nice!!

 

[BillsBackerz67]

Based on your calculations I would still be APL length so its not accurate for my hair.

 

[charmtreese]

This is interesting.

 

[luckiestdestiny]

..............................................................luckiest was here

 

[KittyMeowMeow]

Based on your calculations I would still be APL length so its not accurate for my hair.

Hmmm, did you use the sample equation/100 hairs per day as the shedding amount? For me, the example in the OP works out to about APL. My assumption is that most people shed far less than 100 hairs per day. I read that the vast majority of people can grow to at least WL. On me (I'm 5'4") that's 25"...which would be somewhere in the 50-60 hairs range.

Thank you for testing it out! I realize the OP may be confusing- most ppl will not shed 100 hairs per day so that number will be smaller! Another problem I realized is that most people do not know how many hairs they shed per day, and people would have to be seriously dedicated to wanna figure it out unless it's just a few!

 

[BillsBackerz67]

I shed a lot always have and always will. Most day I can shed up to 120 hairs.....but I never tried to rectify the situation.

 

[KittyMeowMeow]

I shed a lot always have and always will. Most day I can shed up to 120 hairs.....but I never tried to rectify the situation.

Wow, good to know! Is this just on wash day, or do you detangle daily? Is this just shed strands, or is there possibly breakage in there as well? Sorry for all the questions & TIA for any help since I wanna see if/where the variables are going wrong and majorly underestimating TL for some people!

The major pitfall in this thing is the # of hairs on the head. I think there is not much research, and what there is was done a long time ago before modern equipment, and who knows the methods. 100,000 is probably a low estimate - so it would cause TL to be underestimated...

 

[LayneJ]

This is such an interesting thread!

I did some VERY rough estimates (mostly to figure shed hairs per day) to determine my TL using your calculations and I came up with 90 inches:

15 x 365 = 5475
100,000/5,475 = 18
18 x 5 = 90 inches

Thanks for doing the legwork, OP. That was fun!

 

[charmtreese]

Daily I lose anywhere from 0-10 on wash day I lose about 80( but Im gonna say 100), so thats 160 hairs a week.

23 hairs a day X 365 = 8395 (wow, thats a lot of hair!!!)
100,000/8395 = 11.9 years (That seems lika a long time...but I'll take it!)
11.9 X 5 = 59.5 inches (Sounds good to me)

 

[KittyMeowMeow]

This is such an interesting thread!

I did some VERY rough estimates (mostly to figure shed hairs per day) to determine my TL using your calculations and I came up with 90 inches:

15 x 365 = 5475
100,000/5,475 = 18
18 x 5 = 90 inches

Thanks for doing the legwork, OP. That was fun!

Awesome! I'm so glad you enjoyed it! I had fun doing it!

Also, now seeing that my, yours, charmtreese and luckiest (who said she got such a high number that she didn't want to post ) are quite high numbers shows me that there are plenty of black women with the potential to grow extremely long (to the floor and beyond) hair. This board hasn't been around long enough for us to see what's possible, since these terminal times are like 18 years...I believe we will see ladies growing to even more amazing lengths in the years to come. Heck, they already are - you know I'm lurking in that Classic Length thread .

 

[luckiestdestiny]

Awesome! I'm so glad you enjoyed it! I had fun doing it!

Also, now seeing that my, yours, charmtreese and luckiest (who said she got such a high number that she didn't want to post ) are quite high numbers shows me that there are plenty of black women with the potential to grow extremely long (to the floor and beyond) hair. This board hasn't been around long enough for us to see what's possible, since these terminal times are like 18 years...I believe we will see ladies growing to even more amazing lengths in the years to come. Heck, they already are - you know I'm lurking in that Classic Length thread .

Awe you caught me before I edited my post

I didn't want any debates about how little hair shed, or if I'm sure how fast my hair grows....so I just erased it. I really wasn't in a mood for a prove it thing, that you just can't prove. My hair just sheds so very little (from what I see and also from what I retain too), and it does grow fast (shrug). My prob is only manipulation (but I solved that) so now the breakage is really miniscule (and so is the hairs lost from the bulb...never were a lot to begin with).

But I definitely think we can get to great lengths and also I have an attitude that refuses to accept limitations (I mean I won't go jumping off windows but this terminal length thing I think there are other factors that are nuture vs. nature (and even health) related that can change all that...so I just don't want to believe in this whole terminal thing...or at least it being as small as we think). For instance someone posted earlier that they would never have gotten as long as they did according to the calculations. So what if they had taken to this first, and gave up on getting longer, they would've never seen how long they can grow (and will continue to grow I'm sure)

 

[luckiestdestiny]

Hey Op,

What made you think of this equation in particular?

 

[Nonie]

@KittyMeowMeow, can you explain equation #2? Somehow it doesn't make sense to me how that can be true or even comes to be.

So please break down for me how you came up with that conclusion. The other two make sense. That middle one baffled me.

To further explain why that equation doesn't ring true, rearranging it would be:

hairs on head = terminal time x yearly shed rate

Surely that is not true. The rate you shed (number of hairs you LOSE per day) multiplied by the time it takes your hair to grow to its max would not give the number of hair NOT SHED/REMAINING on your head, but rather the total amount of hair you will shed during that time period.

What should be on the right side of that equation is TOTAL AMOUNT OF HAIR SHED DURING TERMINAL LENGTH.

I really don't believe there's a way to know terminal time without actually growing your hair under controlled conditions of sorts: perfectly monitored diet and body health, 100% healthy hair practices...like in a lab where you are institutionalized for about 25 years. That would allow time for your hair to grow at least 3 or 4 times to its terminal length so that an average terminal time can be calculated.

 

[Nonie]

Even if we were to use the argument that knowing how many hairs you shed a day can help you estimate how many years it can take for each of the 10K hairs to eventually shed and therefore an estimate of how long your terminal time is*, then:

For someone who loses 100 hairs a day, then if that^ theory is true,
s/he would take 1000 days for all the hairs to go through the shedding process.
That works out to be a little under 3 years.

Now comes my feather-ruffling point:

For someone who loses 2 hairs a day, it would take 50,000 days for all the hairs to reach shedding = max length for each hair
That means terminal time (term) would be 136 years. LOL

OK, if that is the case, then considering that none of us have been around that long, then I don't thick shedding would have even started yet.

Yes, if you cut your hair today, you will still shed your quota at that TWA length. Why? Coz your hair follicles don't really care how long the hair is; they are just concerned w/ whether their lifetime (term) is over or not. So the reason hair will shed is because at the time of BCing, some follicles were at term time so those hairs that had been growing for years were just about to shed and it was going to happen regardless of what you did to the outside hairs.

So this is my belief: even when you THINK you only lose two hairs, that's a very optimistic view. Shed hair comes out when

• you comb through your hair (usually with a comb whose teeth are so close together as to go between strands enough to not miss any),
  
• slide fingers from base to ends when finger combing like you're stroking your strands
• or brush your hair.
  

If you aren't doing this daily, just because you don't see hair fall doesn't mean it's not there hanging by a thread. If you were to gently tug on a hair that isn't about to shed, it would not come out unless you've got some type of follicular disease or hair loss. But if you were to start sliding your fingers from base to ends holding a very thin section of our hair--so thin that it's as if your hairs are in a line so that you are stroking every single one) and you did that on small sections all through your head, I bet you'd see more hair come out than you realized you were shedding.

*The reason I suggested that rate of shed (if accurate) might help with determining term (assume total hairs count is accurate too) is because when a new hair starts growing, it's because another was shed not too long ago. So let's assume today is the day Hair #1 starts its journey. It obviously will not be shed for a long time. One of the other 99,999 will be shed today, and tomorrow, and so on, until the day Hair #1 and any that were born the same day will celebrate their shed day. If every hair that was older has had its turn and now it's Hair #1's turn to fall out, logic tells me that Hair #1 has grown for as long as it could grow, which would give a good estimate of how long hairs on that head take to grow from birth to shedding, = terminal time.

 

[Nonie]

One final point, it's all well and good to be optimistic and dismiss scientific findings or records or theories (like a lady I know who has no plans of dying before she's 150 ) but if really long growth cycles were as long as we'd like to imagine, then there'd be more Diane Witts than the lengths we see--especially for people who practice very healthy/organic ways of living. But we all know that isn't the norm. Not even for other races. Which is why someone like JJJ, who grows 7 inches or so a year and has been growing it for 8 years or so, turns heads.

 

[ChristmasCarol]

I remember seeing this equation on another board I'm a member of (LongHairCommunity), and the consensus among most of us was that it was fun to fool around with and be encouraged by, but it was not accurate enough to really make any predictions as to true terminal length. I do think, however, that Black women can grow our hair as long as anyone else - with proper care.

 

[Nonie]

sipp100, we probably can, but I do wonder if factors like the ones that decided our hair would shrink or that determined the structure of the strands so that rather than being complete cylinders, we have a groove along the length (seen underneath in this pic):

(Source)
...might mean that our longest hair will never be like that of other races.

Don't get me wrong, I do know our people have grown long hair even in the past. But perhaps because it's too weak and there's strength in numbers or maybe just for easy maintenance, I've only seen it in great lengths when in locs. Since long hair was a sign of beauty among the Ngbandi, then I would assume it was more the norm than the exception judging from this pic from 1905--I wonder what the norm is nowaday. But again locs:

But LongHairDontCare, Happily Me, FlowerHair, Mija, Sera, Jynkx etc give us hope that maybe there's a chance that APL may one day be our majority's idea of "short-medium length".

 

[ChristmasCarol]

I don't believe our terminal length is different from others, but yeah, some of us may have a different structure due to genetics. I haven't had any problems growing my 3 daughters hair to MBL/HL/TBL and other women in my family have very long hair with little effort. So, I dunno.

I think APL is "medium length" for every race. I don't consider hair to be "long" until after full BSL/MBL.

 

[newbeginnings2010]

Hmmm...too much math and science for me. I don't count hairs. Personally, doing this much work to find out why my terminal length is would make my HHJ a lot more frustrating and annoying. I have a hard enough time finding the right products and routines for my hair!

 

[Kurlee]

I did it and it says about 24-28 inches. That's at least WL/Tail bone length, so I'm good.

 

[KittyMeowMeow]

Hey Op,

What made you think of this equation in particular?

Awe you caught me before I edited my post

I didn't want any debates about how little hair shed, or if I'm sure how fast my hair grows....so I just erased it. I really wasn't in a mood for a prove it thing, that you just can't prove. My hair just sheds so very little (from what I see and also from what I retain too), and it does grow fast (shrug). My prob is only manipulation (but I solved that) so now the breakage is really miniscule (and so is the hairs lost from the bulb...never were a lot to begin with).

But I definitely think we can get to great lengths and also I have an attitude that refuses to accept limitations (I mean I won't go jumping off windows but this terminal length thing I think there are other factors that are nuture vs. nature (and even health) related that can change all that...so I just don't want to believe in this whole terminal thing...or at least it being as small as we think). For instance someone posted earlier that they would never have gotten as long as they did according to the calculations. So what if they had taken to this first, and gave up on getting longer, they would've never seen how long they can grow (and will continue to grow I'm sure)

Sorry to bust you! I think it's entirely possible that you have a long TL if you shed very few hairs and grow quickly. I agree with you that people shouldn't use this to give up on hair growing goals- as long as the hair is still getting longer, you're good, and there is no need to worry about it. My thought is that it might be useful for anyone who has no breakage and doesn't trim too much who's hair seems to have stopped growing to see if this might be an issue, and maybe take steps to help it if possible. And also for entertainment purposes

I figured out the equation because I realized that the number of hairs shed would be a reflection of terminal length/time, and I thought it be interesting to figure it out!

 

[KittyMeowMeow]

@KittyMeowMeow, can you explain equation #2? Somehow it doesn't make sense to me how that can be true or even comes to be.

So please break down for me how you came up with that conclusion. The other two make sense. That middle one baffled me.

I looked at it like so: Let's say someone with 100,000 hairs on their head is at TL, and they shed 33,333 hairs per year. Because of shedding, there are some hairs at TL, and others of varying lengths that had previously been shed. After the first year, 1/3 of the hair (presumably the longest) will be shed, and then another 1/3 a year for the next 2 years. By the end of the 3rd year, the hairs that were shed around the first day we started calculating would theoretically be nearing their Terminal time/length and almost ready to shed again. To look at it another way, if 1/3 of the hair sheds per year, by the end of 3 years all of the hair from day 1 would be shed. Does this make sense?


To further explain why that equation doesn't ring true, rearranging it would be:

hairs on head = terminal time x yearly shed rate

Surely that is not true. The rate you shed (number of hairs you LOSE per day) multiplied by the time it takes your hair to grow to its max would not give the number of hair NOT SHED/REMAINING on your head, but rather the total amount of hair you will shed during that time period.

What should be on the right side of that equation is TOTAL AMOUNT OF HAIR SHED DURING TERMINAL LENGTH.

The number of hairs on your head would roughly be the same all the time because after the hair is shed and goes through the short additional phases, it is still on there, even though it is not at TL. If we were to add all the hairs that were shed during the entire terminal time, this should add up to the # of hairs on the head. If I'm understanding what you are saying correctly, the equation is actually measuring the hairs that are shed during terminal length, and we can assume that these are at or near TL that are shed.

I really don't believe there's a way to know terminal time without actually growing your hair under controlled conditions of sorts: perfectly monitored diet and body health, 100% healthy hair practices...like in a lab where you are institutionalized for about 25 years. That would allow time for your hair to grow at least 3 or 4 times to its terminal length so that an average terminal time can be calculated.

I agree that the equation is theoretical and doesn't translate perfectly into the real world. For example, hairs may grow at different rates, or I could even imagine it's possible (not sure) for different follicles to have different TLs. An individual's hair may change in growth rate or # of active follicles on the head over time.

Thank you for posting your thoughts! I have to go to work, but I will respond to the other posts later!

 

[Nonie]

Quote Originally Posted by Nonie

KittyMeowMeow, can you explain equation #2? Somehow it doesn't make sense to me how that can be true or even comes to be.

So please break down for me how you came up with that conclusion. The other two make sense. That middle one baffled me.

I looked at it like so: Let's say someone with 100,000 hairs on their head is at TL, and they shed 33,333 hairs per year. Because of shedding, there are some hairs at TL, and others of varying lengths that had previously been shed. After the first year, 1/3 of the hair (presumably the longest) will be shed, and then another 1/3 a year for the next 2 years. By the end of the 3rd year, the hairs that were shed around the first day we started calculating would theoretically be nearing their Terminal time/length and almost ready to shed again. To look at it another way, if 1/3 of the hair sheds per year, by the end of 3 years all of the hair from day 1 would be shed. Does this make sense?


To further explain why that equation doesn't ring true, rearranging it would be:

hairs on head = terminal time x yearly shed rate

Surely that is not true. The rate you shed (number of hairs you LOSE per day) multiplied by the time it takes your hair to grow to its max would not give the number of hair NOT SHED/REMAINING on your head, but rather the total amount of hair you will shed during that time period.

What should be on the right side of that equation is TOTAL AMOUNT OF HAIR SHED DURING TERMINAL LENGTH.


The number of hairs on your head would roughly be the same all the time because after the hair is shed and goes through the short additional phases, it is still on there, even though it is not at TL. If we were to add all the hairs that were shed during the entire terminal time, this should add up to the # of hairs on the head. If I'm understanding what you are saying correctly, the equation is actually measuring the hairs that are shed during terminal length, and we can assume that these are at or near TL that are shed.

I really don't believe there's a way to know terminal time without actually growing your hair under controlled conditions of sorts: perfectly monitored diet and body health, 100% healthy hair practices...like in a lab where you are institutionalized for about 25 years. That would allow time for your hair to grow at least 3 or 4 times to its terminal length so that an average terminal time can be calculated.

I agree that the equation is theoretical and doesn't translate perfectly into the real world. For example, hairs may grow at different rates, or I could even imagine it's possible (not sure) for different follicles to have different TLs. An individual's hair may change in growth rate or # of active follicles on the head over time.

Thank you for posting your thoughts! I have to go to work, but I will respond to the other posts later!

OK the first part of your response (made this color for ease of reference) I agree with. It basically follows the approximate theory I proposed in post #17 which makes sense. Namely that if you lost 33,333 hairs/year. That means at the end of year one, there'd be about 66,666 hairs that had not been shed that are game during the following year. Which means that out of those, 33,333 will be shed by end of year 2. Leaving 33,333 that have always been on your head and which now will get their turn by the end of year 3.

So yes, when you look at it that way, then the formula you proposed does add up very nicely.

Namely,

total hairs on head/# of hairs shed per year = terminal time.




The second part shown in this color I also agree with. . The number of hairs you lose during the lifetime of your hair growing, is the number of hairs you ever had to start with, because each hair will get its turn. So those not shed in year one, will be shed in year 2, or 3...and so on. Again, I try to explain this in post #17

Still I do not believe anyone's losing as little as 2 or 10 hairs only a day only...as I explain in post #17. I'm happy to explain differently if someone didn't get my argument there.

 

[luckiestdestiny]

I agree that dismissing scientific findings is not a good thing to do. But I don't believe we have figured out terminal length yet enough to tell someone that's it for you. And even in the cases you mention....who knows what they've done to their hair (how they comb, style, oil, etc their hair). So really it's hard to determine this stuff if not impossible, which I you pointed out in another post. Someone's health is definitely a factor, as well as the way we handle our hair, plus genetics, and even things like environment (are you in a hot dry area or cold and do you treat your hair right according to the environment). There's just too many factors for me to just assume terminal length is what some scientist says it is until it is proven time and time again

 

[Nonie]

I agree that dismissing scientific findings is not a good thing to do. But I don't believe we have figured out terminal length yet enough to tell someone that's it for you. And even in the cases you mention....who knows what they've done to their hair (how they comb, style, oil, etc their hair). So really it's hard to determine this stuff if not impossible, which I you pointed out in another post. Someone's health is definitely a factor, as well as the way we handle our hair, plus genetics, and even things like environment (are you in a hot dry area or cold and do you treat your hair right according to the environment). There's just too many factors for me to just assume terminal length is what some scientist says it is until it is proven time and time again.

I do agree, which is why I don't even measure, keep checking progress, counting shed hairs, or worrying about how long it takes to get to whatever...just live well and have fun, and let your hair surprise you. I am with you in the sentiment that you can never really know for sure what one's terminal length is unless they have been practicing really good health habits and hair care habits for many years, in order to have a steady length that can be considered their terminal length.

I do like how Sera started her hair journey just to see what would happen, how long her hair could grow,. She didn't set goals, nor do I think she wondered about how long it took others. She just did what she knew was best for her hair as she learned more about it. And look at where she is 5+ years later: http://www.youtube.com/sera2544

So instead of getting discouraged because you may be the one with a short cycle or creating fantasies that you may never realize and therefore that will only get you down in the end. Just think of this as an adventure with a view to learning and discovering more about your hair.

 

[KittyMeowMeow]

Even if we were to use the argument that knowing how many hairs you shed a day can help you estimate how many years it can take for each of the 10K hairs to eventually shed and therefore an estimate of how long your terminal time is*, then:

For someone who loses 100 hairs a day, then if that^ theory is true,
s/he would take 1000 days for all the hairs to go through the shedding process.
That works out to be a little under 3 years.

Now comes my feather-ruffling point:

For someone who loses 2 hairs a day, it would take 50,000 days for all the hairs to reach shedding = max length for each hair
That means terminal time (term) would be 136 years. LOL

There are probably few, if any people that shed 2 hairs per day on average over the year. If they did, it would effectively mean that they don't have a terminal length that is within their lifetime and their hair can theoretically keep growing, although I assume at some point issues like weathering would catch up with you. [/URL]: At 221 inches (18 ft 5 in), this

OK, if that is the case, then considering that none of us have been around that long, then I don't thick shedding would have even started yet.

Shedding would happen every day, at 2 hairs per day, in that example.

Yes, if you cut your hair today, you will still shed your quota at that TWA length. Why? Coz your hair follicles don't really care how long the hair is; they are just concerned w/ whether their lifetime (term) is over or not. So the reason hair will shed is because at the time of BCing, some follicles were at term time so those hairs that had been growing for years were just about to shed and it was going to happen regardless of what you did to the outside hairs.

I agree.

So this is my belief: even when you THINK you only lose two hairs, that's a very optimistic view.

On most days I lose 2 hairs. On some days when the weather is changing, I lose up to 15. Also, I do lose a few more on wash day- about 4-6 (every 5 days). This is why I rounded up to 15 for the daily average so I would know whatever it was was lower than the estimate.

Shed hair comes out when

• you comb through your hair (usually with a comb whose teeth are so close together as to go between strands enough to not miss any),
  
• slide fingers from base to ends when finger combing like you're stroking your strands
• or brush your hair.
  

If you aren't doing this daily, just because you don't see hair fall doesn't mean it's not there hanging by a thread. If you were to gently tug on a hair that isn't about to shed, it would not come out unless you've got some type of follicular disease or hair loss. But if you were to start sliding your fingers from base to ends holding a very thin section of our hair--so thin that it's as if your hairs are in a line so that you are stroking every single one) and you did that on small sections all through your head, I bet you'd see more hair come out than you realized you were shedding.

I finger detangle daily and stroke my hands down the hair in sections after applying a small amount of water to moisturize. I do this every day. I do not see my own hair on the floor while sweeping as I do with my female roommates. After they shower, there is some hair on the drain cover. This doesn't happen with me (I remove the shed hairs and place them somewhere, and there's no hair in the drain). I had heard that people might lose 100 hairs per day and was certain this couldn't be right- I just did not believe it. I was *shocked* when I started watching YT videos and saw what people were losing (I know most people only detangle on wash day)! I did try to not detangle daily & just do it on wash day once- again, it was a small amount amount. There may be a few hairs here and there that I'm missing, but if so, I do not think many...

*The reason I suggested that rate of shed (if accurate) might help with determining term (assume total hairs count is accurate too) is because when a new hair starts growing, it's because another was shed not too long ago. So let's assume today is the day Hair #1 starts its journey. It obviously will not be shed for a long time. One of the other 99,999 will be shed today, and tomorrow, and so on, until the day Hair #1 and any that were born the same day will celebrate their shed day. If every hair that was older has had its turn and now it's Hair #1's turn to fall out, logic tells me that Hair #1 has grown for as long as it could grow, which would give a good estimate of how long hairs on that head take to grow from birth to shedding, = terminal time.

Exactly! That is what the equation is measuring

 

[KittyMeowMeow]

One final point, it's all well and good to be optimistic and dismiss scientific findings or records or theories (like a lady I know who has no plans of dying before she's 150 ) but if really long growth cycles were as long as we'd like to imagine, then there'd be more Diane Witts than the lengths we see--especially for people who practice very healthy/organic ways of living. But we all know that isn't the norm. Not even for other races. Which is why someone like JJJ, who grows 7 inches or so a year and has been growing it for 8 years or so, turns heads.

I think most people just don't want hair that long (I know I don't ), so we don't see it often! Most people can grow long hair, but probably a smaller percentage can grow it that long. I assume most people have a terminal length that is longer than they'd want to grow.