How to Match an Airplane Belt With Your Trousers: The Complete Guide to Sizes, Colours and Fabrics

Step 1: the width, which your belt loops decide

A single question decides whether a belt sits well: how wide are the belt loops of the trousers you want to wear it with? Slide a finger or a ruler through one of them. If the opening is under 4 cm, take the Slim, 38 mm. From 4 cm up, take the Authentic, 48 mm, the same width as on board. A strap wider than the loop twists and puckers the waistband, and nothing looks worse.

The two widths share the same mechanism: you close the belt with a press and open it with an upward lift. Only the size changes. Tap a width below to see which trousers it suits.

Step 2: the colour, and now it is easy

The eight models fall into two families. Four neutrals replace the black, grey, navy or brown belt of a classic wardrobe: the black POLAR, the grey RUNWAY, the deep navy TRANSATLANTIC and the warm brown SILK ROAD. Four accents are made to be noticed: the deep red AUSTRAL, the signal orange TROPIC, the electric blue PACIFIC and the emerald green AMAZONAS. One rule sits behind every pairing below: never a belt from the trousers' own family, and black on black is the only tone-on-tone exception.

Step 3: the fabric of your trousers

The fabric tells you what a belt will look like on it. Denim is thick and rough, chino cotton smooth, linen creased, wool and flannel fine and flat. Below, six of them up close. Then ten kinds of trousers, each with the width to take, the colours that work and a real belt on a real pair. Every belt is named by its colour first, then its model, like the deep red AUSTRAL belt in the first photo.

The jean: look at the cut before the colour

Denim is thick, the seams are rough and the loops generous: a wide strap feels at home. But the cut changes the answer. Straight, relaxed and wide jeans have loops of 4 cm or more: take the Authentic 48 mm. Slim and skinny jeans have narrower loops: take the Slim 38 mm, otherwise the strap creases. The brushed aluminium buckle goes well with the rivets and the metal button.

Dark jeans: a blank page

A very dark raw jean is almost plain: it imposes no colour, so the strap becomes the colour of the outfit. In the photo, the deep red AUSTRAL belt with a grey sweater is the boldest choice. The warm brown SILK ROAD belt is softer, and the emerald green AMAZONAS belt more unexpected.

Light jeans: a sober grey or a warm strap

Light denim is already blue, so the strap should not be: no blue, and no black either. The grey RUNWAY belt in the photo is the sober answer, which blends in without disappearing. For more character, the deep red AUSTRAL belt is the boldest, the warm brown SILK ROAD belt the softest and the signal orange TROPIC belt the sunniest.

Ecru jeans: navy is the quiet contrast

Ecru and off-white denim is soft, so a dark strap draws a clean line across the waist. The deep navy TRANSATLANTIC belt in the photo does it without shouting. Check the cut here too: straight ecru jeans take the Authentic 48 mm, slim ones the Slim 38 mm.

Black jeans: one colour is enough

Black jeans are the quietest pair you own, so a bright strap stands out more than anywhere else. Take the emerald green AMAZONAS belt from the photo, or the signal orange TROPIC belt. To stay discreet, the black POLAR belt is the one tone-on-tone exception we allow: black on black reads as calm, not as a mistake.

Chinos: from army trousers to everyday classic

Chinos began as military trousers. After the Spanish-American War of 1898, American soldiers brought home the lightweight cotton twill trousers they had worn in the Philippines, and the army made them standard issue within a few years. Like the airplane buckle, the chino is a military object that became an everyday one.

Chinos are the easiest trousers on which to show off a coloured buckle: the fabric is smooth and the loops are narrow, so take the Slim 38 mm. Beige accepts every colour of the collection. The warm brown SILK ROAD belt is the classic, the deep navy TRANSATLANTIC belt the quiet one and the electric blue PACIFIC belt the bold move. Swipe through the photos below.

Navy chinos: never navy on navy

A dark blue pair of trousers calls for a warm answer. In the photo, the signal orange TROPIC belt is the sharpest. The warm brown SILK ROAD belt is the softest and the deep red AUSTRAL belt the boldest. The loops are those of a chino: take the Slim 38 mm.

Olive trousers: never green on green

Olive is close to military colours. A green strap on green trousers would vanish, so bet on warmth: the warm brown SILK ROAD belt in the photo, or the signal orange TROPIC belt. The cut and the loops are those of a chino, so the Slim 38 mm fits.

Cargo trousers: from army to workwear

Like jeans, cargo trousers have a thick fabric and wide loops: the Authentic 48 mm holds its own. Measure first: if the loops are under 4 cm, take the Slim 38 mm.

On charcoal, the signal orange TROPIC belt in the photo stands out best. On sand or ecru, the warm brown SILK ROAD belt is more discreet.

White and cream trousers: the simplest canvas

On white or cream, a coloured strap looks like a deliberate choice. The warm brown SILK ROAD belt in the photo behaves like the classic brown belt, with a more interesting buckle. The deep navy TRANSATLANTIC belt is the sharp one, the electric blue PACIFIC belt the bolder one. Take the Slim 38 mm: these trousers are lighter and their loops narrower.

Linen: the cloth creases, the belt stays crisp

Linen creases and falls loose: the belt does real work there, it holds the waist. Next to those soft folds, a crisp strap in a lively colour stands out cleanly: the Slim 38 mm. The electric blue PACIFIC belt on white linen, below, looks like a summer postcard.

Wool and flannel: the airline pilot's trousers

Wool and flannel are finer than denim, with a clean drape: the Slim 38 mm is the right width. On grey, the black POLAR belt in the photo is the most sober. The deep navy TRANSATLANTIC belt is the calm choice, and the deep red AUSTRAL and warm brown SILK ROAD belts give it character.

Pleated and high-waisted trousers: the belt moves up

A high waist puts the belt closer to the ribs, right where the eye lands, so it becomes the most visible accessory of the outfit. Tuck the shirt in, and choose a strap that lets the pleats stay in front: the warm brown SILK ROAD belt or the deep navy TRANSATLANTIC belt below, on ivory trousers. Take the Slim 38 mm.

Tailoring: the buckle for smart-casual

The most formal dress codes call for a slim dress belt about 3 cm wide, with a small plain buckle. An aircraft buckle is not discreet, so we do not suggest it there. Everywhere else it works: a blazer and trousers, a relaxed office, a dinner. Check one thing first: tailored trousers often have narrower loops than jeans, and the loop must be wider than the strap. Take the Slim 38 mm. In a smart-casual outfit, the buckle is what starts the conversation.

Shorts: check the loops, not the season

The width depends on the loops, as everywhere else. Chino-style shorts have the same loops as chinos, so the Slim 38 mm fits. Cargo and denim shorts are cut like their long cousins, with wider loops: take the Authentic 48 mm. A neutral strap, like the grey RUNWAY belt in the photo, calms things down, while the signal orange TROPIC belt does the opposite. Keep the hem above the knee and let the buckle sit squarely at the front.

Four mistakes to avoid

They are small, and they are the ones we see most often.

One belt for all of it

You already own the trousers. Fly-Belts is the belt that goes with them: the buckle of an aircraft seat belt, redesigned for the waist of a pair of trousers, with an aluminium buckle, a strap in aviation webbing and two widths. The eight colours carry the names of routes, from POLAR to TROPIC.

Start with The Belt at 59 €, or choose The Upgrade at 79 €: one buckle and two interchangeable straps, to change colour from one pair of trousers to the next. The First at 109 € goes one step further, with three straps and one buckle, enough to cover jeans, chinos and tailoring. Delivery is free worldwide.