Find your fit: How to measure shorts inseam for every activity

Small detail. Big difference. Your inseam length can shape how you feel in motion whether you’re sprinting, lifting or stretching through recovery.

A male and female athlete wearing On shorts, showcasing fit and length for a guide on how to measure inseam on shorts.

A great run or workout starts with gear that moves with you. And that begins with shorts that fit just right. Knowing how to measure the inseam on shorts is the simplest way to find your fit.

One size doesn’t fit all. Shorter inseams tend to rule on the track while longer lengths often win in field sports. Your training style, build and comfort preferences all play a role.

Here’s how to measure your inseam, and how to choose the right length for whatever you’re training for.

The inseam, decoded

Your inseam runs from the crotch seam to the hem. Simple to measure, but it makes a big difference to fit and feel.

“Inseam length influences how short the shorts sit on the upper leg,” says On Product Expert, Will Ralf. “A 3” or 5” inseam means less coverage and snugger fit on the quad. A 7” or 9” inseam gives more coverage and a looser feel.”

Shorter lengths often mean more airflow and range of motion. Longer lengths bring coverage and ease. Neither is “better.” Just better for certain bodies, workouts and days.

A male athlete warming up while wearing On performance gear.

The body of an athlete leaning over and catching his breath, wearing On shorts.

Getting it right: How to measure your inseam

There’s no one-size-fits-all answer to the “right” inseam length. The key is knowing yours then experimenting. “Try a new design or a new length and see what you think,” says Ralf. “Fit is personal.”

Step 1: Gather your tools

You’ll need a flexible tape measure and either your favorite pair of shorts or just your own body.

Step 2: Prepare your shorts

Lay them flat and smooth out any folds. Wrinkles can skew your measurement.

Step 3: Locate the crotch seam

This is where the two leg seams meet in the middle. It’s your starting point.

Step 4: Measure

For shorts: measure straight down the inside seam to the hem. For your body: stand tall and measure from your crotch down to where you want the shorts to end.

A woman running outside, wearing an On sports bra and shorts with a sweatshirt tied around her waist.

The right fit, real impact

The right inseam can mean the difference between distraction and focus.

Ralf, over six feet tall, avoids anything under 5” unless layered over a base layer. “Too short can mean chaffing when running from the leg opening,” he says.

Length can vary from season to season too. A cold morning run in shorts that are too short? You’ll notice.

An inseam for every adventure

3-5 inches: Built for speed and intensity

Best for sprints, warm-weather runs and tennis matches where range of motion and cooling matter.

Styles like the 3” Core Shorts and 5” Performance 2/1 Shorts give freedom to move and keep things light.

A female athlete stretching her shoulders, wearing a white sports bra and On running shorts.

A male athlete wearing On workout gear, staring seriously at the camera.

7 inches: Versatility for everyday miles

Balanced coverage and mobility makes this length ideal for gym sessions or year-round wear. Ralf’s go to: On’s 7” Performance Shorts for easy movement during strength or functional training sessions. “I find the 7” inseam length to be the most universal across different activities and seasons,” he says.

A male athlete posing in all-white On performance gear, including shorts, a tank top, and training shoes.

A male athlete standing while wearing an On long-sleeve performance shirt, shorts, and training shoes.

9+ inches: Extra coverage

A solid pick for taller builds, basketball sessions, hikes or slower-paced runs. More fabric means more coverage and a looser fit around the thigh which can help prevent chafing.

A female athlete posing with her hands in her pockets, wearing On shorts and a zip-up jacket.

A male athlete looking serious with hands in his pockets, wearing On shorts and a crewneck sweatshirt .

Feel every stride

Inseam length is one of the many quirks that make up the world of fitness. When you know your inseam, you can choose shorts that move so seamlessly, all that’s left is the joy of movement.

On’s training collection covers every length from 3” Performance Shorts AOP to Train Shorts with a 7” inseam. All shorts are engineered for comfort and support you need. Explore the collection today.