# In total what length of hair do I grow in a day? **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [October 15, 2025, 4:16am UTC](https://boards.straightdope.com/t/in-total-what-length-of-hair-do-i-grow-in-a-day/1023982 "2025-10-15T04:16:11Z")\ **Posts on this page:** 13\ **Page:** 1
**Author:** ![Sooner](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sooner/32/7875_2.png) [@Sooner](https://boards.straightdope.com/u/Sooner)\ **Post date:** [October 15, 2025, 4:16am UTC](https://boards.straightdope.com/t/in-total-what-length-of-hair-do-i-grow-in-a-day/1023982/1 "2025-10-15T04:16:11Z")
I have a very full head of (mostly grey) hair. Only moderately hairy over the remainder of my body. Seems I am always shaving, trimming and such and still find stray long hairs on occasion. So … on a typical day, what is the total length of hair I grow - if totaled? ---
**Author:** ![DMC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dmc/32/18049_2.png) [@DMC](https://boards.straightdope.com/u/DMC)\ **Post date:** [October 15, 2025, 4:42am UTC](https://boards.straightdope.com/t/in-total-what-length-of-hair-do-i-grow-in-a-day/1023982/2 "2025-10-15T04:42:53Z")
Male? On your scalp alone, you have roughly 100,000 hairs, each of which grown .35 mm (a bit over 1/100th of an inch) per day, which totals 35,000 mm or 1,378 inches, so let’s call it 115 feet. You also lose around a hundred hairs a day. If they are 6 inches long, that’s 50 feet you lost, so a net gain of 65 feet a day. I’m not digging into whether you have back hair like a werewolf nor your pubic hair situation, but that should give you a starting point. Note that all of the above are extremely simplified calculations, so the reality could heavy tilt in either direction. ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [October 15, 2025, 11:53am UTC](https://boards.straightdope.com/t/in-total-what-length-of-hair-do-i-grow-in-a-day/1023982/3 "2025-10-15T11:53:54Z")
Cool!! I’d never thought to total it up that way. 115 feet! Not quite 5 feet per hour, so maybe 80% as long as the person themselves. Every hour every day. That’s a bunch of raw material. Well, not really since they’re so fine, but still it’s a surprising number (to me.) ---
**Author:** ![Jasmine](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jasmine/32/2964_2.png) [@Jasmine](https://boards.straightdope.com/u/Jasmine)\ **Post date:** [October 15, 2025, 11:58am UTC](https://boards.straightdope.com/t/in-total-what-length-of-hair-do-i-grow-in-a-day/1023982/4 "2025-10-15T11:58:44Z")
> [@LSLGuy](#): > > ’d never thought to total it up that way. 115 feet! “Rapunzel, Rapunzel, let down your long hair!” 😳 ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [October 15, 2025, 12:53pm UTC](https://boards.straightdope.com/t/in-total-what-length-of-hair-do-i-grow-in-a-day/1023982/5 "2025-10-15T12:53:16Z")
Now if was spider silk, maybe you could climb the one hair strand if you could get a good grip. 😉 Not really, but silk is famously a LOT stronger than mere hair. ---
**Author:** ![Spiderman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/spiderman/32/230_2.png) [@Spiderman](https://boards.straightdope.com/u/Spiderman)\ **Post date:** [October 15, 2025, 1:15pm UTC](https://boards.straightdope.com/t/in-total-what-length-of-hair-do-i-grow-in-a-day/1023982/6 "2025-10-15T13:15:44Z")
> [@LSLGuy](#): > > Now if was spider silk My hair is spider silky! ---
**Author:** ![Jasmine](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jasmine/32/2964_2.png) [@Jasmine](https://boards.straightdope.com/u/Jasmine)\ **Post date:** [October 15, 2025, 1:37pm UTC](https://boards.straightdope.com/t/in-total-what-length-of-hair-do-i-grow-in-a-day/1023982/7 "2025-10-15T13:37:37Z")
> [@LSLGuy](#): > > Not really, but silk is famously a LOT stronger than mere hair. Yes! I looked it up and found this: Spider silk is stronger than steel by weight, making it one of the toughest biological materials known. For example, a single pencil-width strand is strong enough to stop a Boeing 747 jet, and its toughness is more than twice that of Kevlar ---
**Author:** ![Robot\_Arm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/robot_arm/32/18280_2.png) [@Robot\_Arm](https://boards.straightdope.com/u/Robot_Arm)\ **Post date:** [October 15, 2025, 2:18pm UTC](https://boards.straightdope.com/t/in-total-what-length-of-hair-do-i-grow-in-a-day/1023982/8 "2025-10-15T14:18:18Z")
How does that compare to human hair? I had hair down to my shoulder blades many years ago. Occasionally I would find a strand that had deserted its post. They were long enough that I could wrap the ends around my fingers and pull. It was surprisingly stretchy, and I was able to break it. I had a thought a while ago for a thread about the physical properties of biological things; tensile strength, and such. Maybe I’ll finally start it. ---
**Author:** ![DMC](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dmc/32/18049_2.png) [@DMC](https://boards.straightdope.com/u/DMC)\ **Post date:** [October 15, 2025, 3:38pm UTC](https://boards.straightdope.com/t/in-total-what-length-of-hair-do-i-grow-in-a-day/1023982/9 "2025-10-15T15:38:37Z")
> [@LSLGuy](#): > > Cool!! > > I’d never thought to total it up that way. 115 feet! Not quite 5 feet per hour, so maybe 80% as long as the person themselves. Every hour every day. I’ll be honest. I initially thought the question was slightly silly as I assumed the answer was some nominal value. Once I started doing the math it dawned on me that it was actually a very interesting question that back in the day would have made for a good column. ---
**Author:** ![Folly](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/folly/32/3219_2.png) [@Folly](https://boards.straightdope.com/u/Folly)\ **Post date:** [October 21, 2025, 6:56pm UTC](https://boards.straightdope.com/t/in-total-what-length-of-hair-do-i-grow-in-a-day/1023982/10 "2025-10-21T18:56:29Z")
XKCD also estimated 5 ft/hr. [![](https://www.explainxkcd.com/wiki/images/c/c4/hair_growth_rate.png) ](https://www.explainxkcd.com/wiki/images/c/c4/hair_growth_rate.png) ---
**Author:** ![WildaBeast](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/wildabeast/32/6_2.png) [@WildaBeast](https://boards.straightdope.com/u/WildaBeast)\ **Post date:** [October 21, 2025, 7:28pm UTC](https://boards.straightdope.com/t/in-total-what-length-of-hair-do-i-grow-in-a-day/1023982/11 "2025-10-21T19:28:33Z")
On a somewhat related note, I just recently learned from an episode of _Science Friday_ that if you transplant a head hair onto another part of your body, like, say, your leg, it will continue to grow like a head hair. Just in case you want to grow some really long hairs on your legs. That’s kind of a silly example, but it illustrates the principle of “donor dominance”, which apparently why for balding men, transplanting hair from the back of the head, which is less sensitive to testosterone, to the top of the head, actually works. > **[The Science Of Replacing Body Parts, From Hair To Hearts](https://www.sciencefriday.com/segments/replaceable-you-book-transplants/)** > > In “Replaceable You,” Mary Roach describes mind-boggling efforts to replace human body parts—and why it’s proven to be so difficult. ---
**Author:** ![mixdenny](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mixdenny/32/2962_2.png) [@mixdenny](https://boards.straightdope.com/u/mixdenny)\ **Post date:** [October 25, 2025, 5:23pm UTC](https://boards.straightdope.com/t/in-total-what-length-of-hair-do-i-grow-in-a-day/1023982/12 "2025-10-25T17:23:15Z")
> [@Jasmine](#): > > Spider silk is stronger than steel by weight, making it one of the toughest biological materials known. I have often wondered about the tensile strength of celery strings. Some plants (aloe?) have long strands and a hard pointed tip at the end of the leaf and they can be extracted and used as wilderness needle and thread. I watch way too many survival videos. But I never get lost. I do glance around the woods around my lot and see if I can spot any good places to build a survival hut in case I get lost 50 feet from the house. ---
**Author:** ![Jasmine](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jasmine/32/2964_2.png) [@Jasmine](https://boards.straightdope.com/u/Jasmine)\ **Post date:** [October 27, 2025, 11:31am UTC](https://boards.straightdope.com/t/in-total-what-length-of-hair-do-i-grow-in-a-day/1023982/13 "2025-10-27T11:31:30Z")
> [@mixdenny](#): > > I watch way too many survival videos. With the way things are going, I wouldn’t be too sure about that. LOL