Formal Trousers for Men: Flat-Front, Pleated or Side-Adjuster?

Choose flat-front formal trousers if you are slim through the hip and want the cleanest line. Choose pleated trousers if you have a fuller seat or thigh, sit for long periods, or prefer a higher waist. Choose side adjusters if you want to wear tailoring without a belt. Those three decisions (front, rise and waistband) matter more than colour, and they are what this guide covers.

Trousers do more of the work in an outfit than they are given credit for. A jacket is taken off within the hour at most events. The trousers stay. They set the proportion of the leg, decide whether a shirt stays tucked and determine how the shoe is seen. A man who gets his trousers right looks well dressed in a plain white shirt. All five cuts below are from the Christopher Noir Formal Trousers collection.

Which formal trouser cut suits you?

Flat-front or pleated: which is better?

Neither. They solve different problems. A flat front lies smooth from waistband to thigh, which looks sharp on a slim frame and under a shorter, modern jacket. A pleat is a fold of extra cloth that opens when you sit or move, so the trouser does not pull across the lap. Pleats went out of favour when they were cut too full. Cut properly, they are more comfortable and often more flattering.

The Noir Burford is the flat-front reference: a smooth, uninterrupted line from waist to hem, a pressed crease, belt loops at a mid-rise waistband and a slim, gently tapered leg in charcoal wool.

The Noir Painswick is the single-pleat answer: one forward pleat either side for comfort through the hip, with room through the seat and thigh easing to a straight leg, in mid grey.

When should you wear double pleats and a high waist?

When you want the longest possible leg line. A high rise places the waistband at the natural waist, which lengthens the leg and keeps a shirt or kaftan-length tunic lying flat. Double pleats give the hip room that a high waist needs. The Noir Broadway has twin forward pleats, an extended waistband tab, side adjusters in place of belt loops and a crease tapering to a narrow hem, in cream. It is the trouser for warm-weather events and evening dress, and it pairs well with an isi agu or a dark jacket.

Belt loops or side adjusters?

Side adjusters are small buckled tabs at each hip that tighten the waistband. They remove the belt, which removes a horizontal line across the middle of the body. The result is cleaner under a jacket and a waistcoat. Belt loops are more familiar and allow a belt to tie in with your shoes. The Noir Bourton is a navy side-adjuster trouser with a flat front and a slim-straight leg, worn without a belt. If you prefer loops, read how to choose a leather belt.

Can you wear pinstripe trousers without the jacket?

Yes, and it is one of the more confident ways to wear them. With a plain knit or a white shirt, a pinstripe trouser carries the outfit alone. The Noir Chipping has a fine chalk-toned pinstripe on a deep navy ground, a flat front and a straight leg with a slight break over the shoe.

Which wool should you choose?

Four of these trousers are offered in five wool grades, selected on the product page: Tropical Wool, Italian Tropical Wool, Super 100s Virgin Wool, Super 130s Virgin Wool and Super 100s Merino Wool. Tropical wools are lighter and suited to warm rooms. Higher Super numbers indicate finer yarn and a smoother hand. We explain the differences in Suit Fabrics, Explained.

How should formal trousers fit?

1. The waistband stays up without a belt.
2. The seat lies smooth, with no pulling at the pockets.
3. The crease hangs straight from hip to hem.
4. The hem touches the shoe with a slight break, or none on a tapered leg.

Frequently asked questions

What sizes are available?

All five are sized by waist from 28 to 40. Each product page advises taking your usual waist size.

How do I care for wool trousers?

Dry clean only. Hang them by the hem and steam between wears.

What colour should I buy first?

Charcoal or navy. Both work with black and brown shoes and with most jackets.

Which shoes go with formal trousers?

An oxford or derby for business, a loafer for less formal days. See our guide to men's formal shoes.