Your inseam is the measurement behind every “short, regular and long” label on trousers and jeans. It is easy to measure on a pair of pants, yet harder on your own body without help. This calculator estimates it from your height using a ratio taken from a large body-measurement survey, and it shows how much spread to expect, so you can order a length and then check it on a real pair of trousers.
How to use the inseam calculator
- Enter your height without shoes, in centimetres, inches or feet.
- Choose the proportions: men’s, women’s or the average of both.
- Set the hem gap if you want a trouser length: how far above the floor the hem should finish. This is your choice and depends on shoes.
- Read the result: the estimated body inseam, the likely range, and the trouser inseam with your hem gap.
Inseam formula
likely range = height × (ratio ± SD)
trouser inseam = body inseam − hem gap
The ratio is the mean of crotch height ÷ stature in the ANSUR II anthropometric survey of US Army personnel (4,082 men and 1,986 women, published 2012), calculated directly from its public data files on 2026-10-15. The survey describes military personnel, not the whole civilian population, so the ratio is a good guide rather than a promise for everybody.
| Group | People | Mean ratio | Standard deviation |
|---|---|---|---|
| Men | 4,082 | 0.4815 | 0.0141 |
| Women | 1,986 | 0.4802 | 0.0151 |
| Both | 6,068 | 0.4811 | 0.0145 |
Estimated inseam by height
| Height | Estimated inseam (men) | Estimated inseam (women) | Likely range, men (±1 SD) | Likely range, women (±1 SD) |
|---|---|---|---|---|
| 150 cm (59.1 in) | 72.2 cm (28.4 in) | 72.0 cm (28.4 in) | 70.1 – 74.3 cm | 69.8 – 74.3 cm |
| 160 cm (63.0 in) | 77.0 cm (30.3 in) | 76.8 cm (30.2 in) | 74.8 – 79.3 cm | 74.4 – 79.2 cm |
| 170 cm (66.9 in) | 81.9 cm (32.2 in) | 81.6 cm (32.1 in) | 79.5 – 84.3 cm | 79.1 – 84.2 cm |
| 180 cm (70.9 in) | 86.7 cm (34.1 in) | 86.4 cm (34.0 in) | 84.1 – 89.2 cm | 83.7 – 89.2 cm |
| 190 cm (74.8 in) | 91.5 cm (36.0 in) | 91.2 cm (35.9 in) | 88.8 – 94.2 cm | 88.4 – 94.1 cm |
| 200 cm (78.7 in) | 96.3 cm (37.9 in) | 96.0 cm (37.8 in) | 93.5 – 99.1 cm | 93.0 – 99.1 cm |
Worked example
A man is 180 cm tall and wants trousers that finish 1 inch above the floor.
- Body inseam: 180 × 0.4815 = 86.7 cm (34.1 in).
- Range (±1 SD): 84.1 – 89.2 cm.
- Trouser inseam: 86.7 − 2.54 = 84.1 cm (33.1 in), so a 33 in ready-to-wear length would be the nearest standard size.
Measuring your inseam directly
- On your body: stand barefoot against a wall, feet shoulder-width, and hold a level book high in your groin. Measure from the top of the book to the floor.
- On trousers: lay a well-fitting pair flat, and measure the inside seam from the crotch seam to the bottom of the hem.
- Take it twice, and average if your legs differ. A tailor can take the figure for you.
A direct measurement beats any estimate, especially if your legs are long or short for your height. Compare the result with the waist-size information in the Pants / Trouser Size Calculator and Jeans Size Calculator, and see the Belt Size Calculator for belts. The calculator gives a general estimate and does not replace a tailor’s measurement.
Sources
Every figure above comes from these pages, read directly on the dates shown.
- The OPEN Design Lab — ANSUR II (US Army anthropometric survey, 2012): description and data files — checked 2026-10-15
- ANSUR II public data — men (crotchheight and stature columns) — checked 2026-10-15
- ANSUR II public data — women (crotchheight and stature columns) — checked 2026-10-15
Frequently asked questions
What is an inseam?
The inseam is the length of the inside of the leg, from the crotch seam down to the hem. For your body, it is the distance from the crotch to the floor, which is what this calculator estimates. For a pair of trousers it is measured on the garment, flat, from the crotch seam to the hem.
How is the estimate calculated?
The calculator multiplies your height by the average ratio of crotch height to stature measured in the ANSUR II survey: 0.4815 for men, 0.4802 for women and 0.4811 for both. The likely range is one standard deviation either side.
How accurate is it?
About two thirds of people in the survey fall within the range shown, which is roughly ±2.5 cm (an inch) around the estimate. People with unusually long or short legs for their height will be outside it, so a direct measurement is always better.
How do I measure my inseam directly?
Stand barefoot with your back to a wall, heels together, and hold a book or ruler level between your legs at the top. Measure from the top of the book to the floor. Or lay well-fitting trousers flat and measure the inside seam from crotch to hem. See also Pants / Trouser Size Calculator.
Why is there a hem gap setting?
Trousers do not reach the floor, and how far they stop above it is a style choice that depends on shoes and fashion. The setting lets you subtract your own choice from the body inseam to get a trouser length.