Most people judge jeans on the leg, which is the part that is a matter of taste. The parts that decide whether a pair works are the waist and the seat.

The waist — no gap, no dig

Fasten them and check the back. A gap at the rear waistband means the rise is wrong for your proportions, not that the size is wrong — going down a size will make the gap worse while making everything else tight.

The waistband should sit against you all the way round with room for a couple of fingers. If it digs when you sit, it is too small regardless of how it feels standing.

Always check sitting down. A waistband that is comfortable standing and painful seated is the single most common buying mistake.

The seat — smooth, not straining

Look at the back in a mirror.

  • Horizontal creases under the seat mean they are too tight
  • Sagging, empty fabric means too loose
  • Smooth with a little shaping is right

The seat is difficult and expensive to alter, so treat it like a shoulder on a jacket: get it right in the shop.

The rise — where the waistband sits

Rise is the distance from crotch to waistband, and it decides comfort more than any other measurement.

  • High rise sits at the natural waist. Suits longer torsos; can feel like it reaches the ribs on a short torso.
  • Mid rise sits between waist and hip. The most universally comfortable.
  • Low rise sits on the hips. Suits shorter torsos.

If jeans have never felt right, the rise is the first thing to check. Dressing for your proportions explains why torso length decides this.

The crotch

There should be no pulling and no significant excess. Fabric bunching below the crotch usually means the rise is too long; strain across it means too short or too tight.

This is the area people are most reluctant to examine in a changing room and it is worth the thirty seconds.

The leg and the hem

The leg shape — slim, straight, wide, bootcut — is entirely a style decision and should follow the shoe you intend to wear.

Length is not optional though:

  • Full length with a heel — roughly half an inch off the floor
  • Full length with a flat — just brushing the top of the shoe
  • Cropped — at or just above the ankle bone, deliberately

Hemming jeans is inexpensive and it is what separates a pair that fits from a pair that fits you. Ask for the original hem to be retained if the wear on it matters to you.

Trying them on properly

  • Wear the shoes you will wear with them, or bring them
  • Sit, squat and walk before deciding
  • Give rigid cotton five minutes to warm up — it relaxes on the body
  • Ignore the number on the label entirely

Sizing for the fabric

The composition changes how to size.

Rigid cotton gives about half a size within a week, so buy it snug. Stretch denim already accommodates you, so buy true — sizing up leaves it loose within hours.

How to stop jeans stretching covers washing them so the recovery lasts, and reading a composition label covers what the percentages predict.