How to measure inseam, and how it differs from outseam

Inseam is the leg length of pants measured along the inside of the leg: on your body, from the crotch to the floor without shoes; on the pants, from the crotch seam to the hem. Outseam is measured down the outside of the leg, from the top of the waistband to the hem. Size charts and pant labels use the inseam: in "32/32" or "W32 L32", the second number is the inseam in inches.

How to measure your inseam on your body

It is easier with a helper, and a hardcover book does the job of a tailor's hand.

1. Take off your shoes and stand on a hard floor, back straight, feet slightly apart.
2. Wear close-fitting pants or underwear, not baggy trousers.
3. Place the book between your legs, spine up, and lift it gently until it touches the crotch, keeping it level.
4. Measure from the top of the spine straight down to the floor. Alone, stand with your back to a wall, hold the book against it, mark the wall at the spine, step away and measure from the mark to the floor.
5. Note the number and the unit. Ruban Size's templates phrase the step as "from the crotch to the floor along the inside of the leg, without shoes."

How to measure the inseam of pants that fit

Often the better number, because it already includes the length you like.

1. Lay the pants flat, front up, legs together and smooth.
2. Fold one leg back to show the inside seam of the other.
3. Measure from the crotch seam, where the four seams meet, to the bottom of the hem, along the inside seam.

And the outseam

Lay the pants flat and measure from the top of the waistband straight down the outside of the leg to the hem. The difference between outseam and inseam is mostly the rise, the distance from the crotch to the top of the waistband, which is why two pants with the same inseam can have different outseams. Outseam appears on garment specs more than on shoppers' charts: none of Ruban Size's 39 templates has an outseam row.

Common mistakes

• Measuring with shoes on, or to where you'd like the hem with heels.
• Not reaching the crotch. Stopping a few centimeters short is the reason the book trick exists.
• Following the front crease of the pants instead of the inside seam.
• Measuring the outseam when the chart asks for the inseam.
• Using a stretched or cropped pair as your reference.
• Mixing body and garment inseams. A body inseam goes to the floor; a garment inseam ends at the hem, usually above it.

Inseam in the templates

Inseam is a length, not a circumference, so charts give one value per size, sometimes the same for every size:

The tall inseam of the Scrubs template is 8 cm longer in every size (84 against 76 cm for an XS, 89 against 81 cm for a 3XL): a length option, not a different size. Petite sizes go the other way; their note says they are "cut for a height of 163 cm (5 ft 4 in) and under: shorter sleeves, legs and torso." For what petite and tall mean, see petite, tall, plus size, big and tall.

For reference, 30 in is 76.2 cm, 31 in is 78.7 cm and 32 in is 81.3 cm.

What it means for a Shopify store

If a style comes in lengths, show the inseam of each length, not only the waist. The Scrubs template does it with two inseam lines under the girths, regular and tall; Find my size reads the regular one and says when an inseam goes past it. With length as its own option on the product (Regular, Tall), shoppers pick the size by the body and the length by the inseam.

Say whether the inseam is the body's (to the floor) or the garment's (to the hem). A garment inseam of 76 cm and a body inseam of 76 cm are not the same pants. The waist matters as much as the length, so link your waist measuring guide from the same chart.

How Ruban Size handles the inseam

The templates with an inseam row, the Scrubs template and the Leggings and activewear template among them, have the inseam step in their How to measure block, linked to the inseam: when a shopper points at or taps it, the inseam line lights up between the legs of the body figure, and the inseam row lights up in the table. The Men's pants template, which has no block of its own, gets a collapsed How to measure section with waist, hips and inseam, built from its table.

Find my size treats the inseam as a length. It picks the size by waist and hips, and the inseam counts for little and never pulls the answer far: short pants are short, not unwearable. When every size has the same inseam, it says so instead of using it; on the Men's pants template a shopper reads "Inseam 30 in: the same for every size". A leg longer than the inseam of the chosen size is named too. On the leggings template, a 76 cm inseam with M measurements reads "Inseam 76 cm: M, above this size's range", so the shopper knows to look at the length.

Questions

Is inseam measured with shoes on?

No. On the body, inseam runs from the crotch to the floor without shoes. If you wear heels or boots with the pants, measure the inside seam of a pair you like with those shoes.

What is the difference between inseam and outseam?

Inseam runs along the inside of the leg, from the crotch to the hem. Outseam runs along the outside, from the top of the waistband to the hem, so it also includes the rise.

What does 32x32 mean on pants?

A 32 in waist and a 32 in inseam. The first number is the waist size, the second the leg length along the inside seam.

How do I measure my inseam without help?

Stand with your back to a wall, hold a hardcover book level between your legs, spine up and touching the crotch, mark the wall at the spine, and measure from the mark to the floor. Or measure the inside seam of pants that fit.