Flat front or pleats?

A pleat is a fold of fabric at the front of the trouser waistband that opens as you move. Through the 2000s and 2010s flat fronts were the only respectable option; that has relaxed, and both are correct now.

Flat front

No fold. The cleanest line across the front of the hip, and the most modern. It suits a slimmer build and a narrower leg, and it is what most people picture when they picture a suit today.

The catch: with nothing to give, a flat front pulls and strains across the thigh if the trouser is cut close and you sit down a lot. If you have muscular legs, you either size up or accept the creasing.

Single pleat

One fold facing outward. It adds room across the front of the thigh exactly where you need it when you sit, and it releases when you stand so the line stays clean. It is the quiet compromise, and it flatters most builds.

Double pleat

Two folds. Noticeably more traditional, more room again, and it pairs naturally with a wider leg and a higher rise. If you like the look of a 1940s trouser, this is how you get it. On a slim modern cut it looks confused.

Athletic thighs, or a job where you sit all day: a single pleat will be more comfortable than you expect, and nobody will read it as old-fashioned.

It goes with the rise

Pleats want a higher waist to sit properly — they open from the waistband, so if the waistband sits low on your hips there is nowhere for them to go and they gape. If you are choosing pleats, choose a mid or high rise with them, and let the trousers sit where your natural waist is rather than down on the hip bones.