In total what length of hair do I grow in a day?

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?

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.

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.)

“Rapunzel, Rapunzel, let down your long hair!” :flushed:

Now if was spider silk, maybe you could climb the one hair strand if you could get a good grip. :wink:

Not really, but silk is famously a LOT stronger than mere hair.

My hair is spider silky!

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

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.

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.