Hair shedding calculator

How much shedding is normal

Shedding 50 to 100 hairs a day is normal, and more on wash days if you wash less often. Hairs that are ready to fall mostly come out when you wash or brush, so a wash-day count after several days without washing is a few days of shedding at once, not one day's. Long hair looks like far more in the drain than short hair; the number of hairs is what counts, not the size of the clump. A big day in the brush after a week of little shedding is usually catch-up, not a change.

Some dermatology sources put the upper edge of normal higher, around 150, and the 100-a-day figure is arbitrary rather than a hard line. That is why the calculator asks about wash days, hair length, triggers and how long it has been going on, instead of comparing one number with one threshold.

The pull test

Dermatologists use a simple test you can do at home, and it reads shedding better than a drain count.

1. Take a small bunch of about 40 to 60 hairs between your thumb and first two fingers, close to the scalp.
2. Slide your fingers firmly but gently along the hairs to the ends.
3. Count what comes away. Two hairs or fewer is normal. Repeat in 2 or 3 spots.
4. More than that in several spots suggests active shedding. Recent research says you do not need to skip washing beforehand.

Shedding or hair loss?

Shedding (telogen effluvium) usually looks like a sudden rise in hair everywhere, not in one zone; a start 2 to 3 months after a trigger such as illness, fever, surgery, childbirth, a crash diet, a new medication or a very stressful stretch; a thinner ponytail but a normal hairline and no bald patches; and settling within about 6 months, with short regrowth along the hairline.

Pattern hair loss usually looks like gradual thinning in a pattern (temples and crown in men, the part and top in women), finer and shorter hairs in those zones while the sides stay thick, and little change in daily shedding: the hair just does not come back as thick.

The two can happen together, and a shedding episode often reveals pattern loss that was already there. A dermatologist can confirm which is which with a magnifier and, if needed, blood tests for iron and thyroid.

When shedding becomes a dermatologist visit

• Hair coming out in handfuls, suddenly, over a few weeks: See a dermatologist this week.
• Shedding with round bald patches, or a red, painful, itchy or scaly scalp: See a dermatologist this week.
• Shedding along with tiredness, unexplained weight change, feeling cold or hot all the time, or changes to your periods: See a dermatologist this week.
• Shedding that began within a few months of starting a new medication: see a dermatologist this week. Do not stop the medication on your own; ask the prescriber.
• Shedding that has gone on for more than 2 to 3 months, even if it is lighter now: book a dermatologist in the next few weeks.
• Shedding after an illness, surgery or childbirth that is still heavy more than 6 months later: see a dermatologist this week.
• Above the normal range once, otherwise well, with a trigger in the last 3 months: Keep watching for up to 3 months. Count again on 3 wash days, do the pull test, and take the four photos monthly.

Read the long version in normal hair loss in the shower and telogen effluvium.

Sources

The 50 to 100 figure follows the American Academy of Dermatology, Mayo Clinic, the NHS and Cleveland Clinic; the wider 30 to 150 range and the shedding timeline follow the British Association of Dermatologists telogen effluvium leaflet; the pull test follows McDonald and colleagues (2017) and Dhurat and Saraogi (2009). Each linked guide names its sources in full.