How to Measure Yourself for a Suit, From 40R to EU 50

The short answer

Take your chest, your height, the trouser waist at the height your suit trousers will sit, and a leg length to the chart of the suit you want, not to the size you wore last time. The general method for the tape is in our guide to measuring yourself for clothes; this page covers what is particular to a suit.

Once the jacket is on, look at the shoulders before anything else. Suitsupply’s jacket fit guide wants the shoulder resting along your own with no overhang, adding, “If it fits well here, you’ll know the jacket is the correct base size.”

Key rule: Choose the size by chest and shoulders, the length letter by sleeve and back length, and leave the jacket waist, sleeves and hems to the tailor.

What 40R means

The number is the chest. Oliver Wicks, a made-to-measure maker, says that in the US system it “is designed to be close to your actual chest measurement in inches”, but “can vary significantly by brand and region”. Proper Cloth suggests a jacket size about one inch below your chest for a slimmer fit, while Charles Tyrwhitt’s UK chart lists each size against the body chest it fits up to, so a man who measures 41 inches reads across to a 42.

The letter is the length of the jacket body and sleeves, chosen by height, and this is where makers disagree most.

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So a man of 6 foot is a Regular at Brooks Brothers and a Long at Oliver Wicks. A jacket you already wear, measured flat, is the firmer check.

The drop between jacket and trousers

Oliver Wicks defines the drop as “the fixed difference in size between a suit jacket and the trousers it is sold with” and says “The industry standard is a 6-inch drop”, so a 40 jacket comes with 34 trousers. It says the standard is designed for a statistically average man, so an athletic build with a large chest and slim waist has to compromise off the rack.

Subtract your trouser waist from your jacket size before you shop. If the answer is not six, look for suits sold in separate sizes; Suitsupply’s page for its navy Havana suit invites you to “Pick your size for each individual item”, with jackets and trousers in their own size runs. Where a suit comes only as a set, buy the jacket that fits and ask a tailor how far the trouser waist can move.

US, UK and European suit sizes

UK and US jackets share the chest number. Suitsupply labels its navy Havana jacket “EU 50 / US 40 / UK 40”, and Hockerty, a made-to-measure maker, agrees, writing that “If you normally buy a UK 40, that corresponds to an EU 50, a US 40”. On Suitsupply’s labels the short and long versions change the European number instead of adding a letter, so a 40 Short is EU 25 and a 40 Long is EU 98, and its 34 trousers are EU 50, the same number as the 40 jacket they pair with under a six-inch drop.

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Oliver Wicks’s chart puts a US 40 at Euro 48, and the article itself warns that “sizing can vary, especially between US and European brands”. Read the chest figure beside any European number.

The jacket measurements that decide the fit

Shoulders come first. Proper Cloth’s alterations guide says “We don’t generally recommend having a tailor adjust the Shoulder Width of a tailored jacket”, Hockerty calls the shoulders the hardest area to alter, and Oliver Wicks puts shoulders, collar and overall length first, “as these are the most difficult and expensive parts to adjust”. Suitsupply describes a shoulder that is too loose as leaving a divot on the arm towards the back of the sleeve head.

The chest has a little room. For its own jackets Proper Cloth allows about 0.4 inch more across the chest and up to 1 inch less, measured flat. Buttoned, Oliver Wicks says, the jacket should not pull or form an “X” shape around the button.

Jacket length is close to fixed. Proper Cloth says “The Center Back Length cannot be adjusted by a tailor, as there is not enough hem material for the jacket to be lengthened properly”, and that shortening brings the pockets and buttons too close to the hem. Suitsupply’s target is that “your jacket’s hem should only just cover your bottom”; Proper Cloth’s is the base of the seat at the back and the base of the fly at the front.

The sleeve is the easiest of the four. Proper Cloth lengthens or shortens its own by half an inch and warns that working cuff buttons limit shortening. Suitsupply wants “half an inch (1.5cm) of your shirt sleeve visible”; Oliver Wicks allows a quarter to half an inch.

Our guide to what a tailor can change on a suit covers the rest, with UK prices.

Measure a jacket that already fits you

Proper Cloth’s method is to button the jacket fully and lay it on a flat, hard surface. Face down, measure the shoulders from where one shoulder seam meets the sleeve straight across to the same point opposite, and the back length from where the collar meets the centre back seam down to the hem. Face up, measure the sleeve from the top of the shoulder seam, over the curve of the sleeve head, to the end of the cuff, and the chest straight across from armpit to armpit.

That chest figure is a flat width, half the jacket’s circumference, so 21 inches flat is 42 inches round. Proper Cloth’s own chest, midsection and hip widths are taken flat, which it says to multiply by two for the circumference. Charles Tyrwhitt’s chart gives a garment chest of 42.5 inches for its slim-fit 40 and 43.5 inches for its classic-fit 40; both are larger than the 40-inch chest the size fits, so they read as full circumferences. Double your flat chest to compare with a chart like that, never with a chart of flat widths, and ask the retailer when a chart does not say.

Sleeve and back length are never doubled. A jacket of yours measuring 25.5 inches in the sleeve and 29.5 inches down the back matches Charles Tyrwhitt’s slim-fit 40 Regular, provided you measured the way its chart does.

The trouser measurements

The waist starts with where the trousers will sit, and makers place it differently. Oliver Wicks says “Measure at your belly button for higher rise trousers, and two to three fingers below it for low-rise”; Proper Cloth puts the waist of its trousers on or just above the hip bones; Hockerty’s measuring guide has you put trousers on, without a belt, and measure “at the height where you want your pants to stay”. Choose the rise, then measure the waist there. For the seat, Oliver Wicks keeps two fingers under the tape so the pockets do not flare.

The rise is the trouser number to get right in the shop. Gentleman’s Gazette’s trouser fit guide says “You can never change the rise”, and Proper Cloth says the rise of its trousers “cannot be adjusted by a tailor as they affect too much of the trouser’s basic structure”.

Length is an inseam, from the crotch seam down the inside of the leg, or an outseam, from the top of the waistband down the outside. Indochino uses the outseam and notes that “off the rack leg length tends to be measured from the inseam”; Hockerty’s standard end point for the outseam is the top of the heel of the shoe.

Suit trousers may also arrive unfinished. Brooks Brothers’ suit size guide lists unfinished inseams of 35 inches for Short, 37 for Regular, 39 for Long and 41 for Extra Long, and Gentleman’s Gazette notes that unfinished trousers carry no second size number. The hem is then set to the break you want, in your own shoes.

Gentleman’s Gazette’s break guide defines a full break as “a noticeable dent in the front of the pants but none in the back”, a half break as a slight dent at the front and no break as a hem that does not touch the shoe; dents at front and back mean the trousers “are simply too long”. Proper Cloth reckons each step, full to half or half to none, takes about half an inch off the inseam. Our dress trousers guide covers the break options in more detail.

Your jeans size is a poor guide. Hockerty warns against “guessing your size based on jeans or shirt labels”, and Indochino’s example is a writer who wore a 33 waist off the rack but measured 36.5 inches. Gentleman’s Gazette adds that casual trousers “can sit lower if you like that style”.

Made-to-measure forms and ready-to-wear charts ask different questions

A ready-to-wear chart turns your body into a size. A made-to-measure form asks for more, and forms disagree on whether they want your body or a garment.

Indochino says “we use your body measurements to create your unique clothing pattern” and that it cannot use the measurements of a suit you own. Proper Cloth works the other way. “Body measurements and the dimensions used for your Proper Cloth orders are quite different,” it says, and its order dimensions are garment widths and lengths. Hockerty’s measuring guide asks for numbers no ready-to-wear chart does, among them a jacket length measured down the front from where the shoulder seam meets the neck, the thigh, the bicep and the full crotch from back waistband to front.

So follow the diagram on the form in front of you and never copy a number from one maker’s form into another’s. Our guide to bespoke, made-to-measure and ready-to-wear explains where each kind of suit sits.

A try-on check in the shop

Wear the shirt and shoes you will wear with the suit, because the cuff and the shoe set the sleeve and the hem.

Look at the shoulders first; a seam that overhangs or a divot at the top of the sleeve means another size or cut. Fasten the jacket and check it closes without an X at the button, with the collar, in Suitsupply’s words, “resting naturally against the shirt collar, with neither significant pressure nor gaps between the layers”. Let your arms hang. The hem should just cover your seat and about half an inch of shirt cuff should show. Reach forward and raise both arms to feel whether the back or the armholes bind.

Then sit down in the trousers, as Gentleman’s Gazette advises, and check whether the waistband digs in or the seat feels tight. Stand, and check the hem in your own shoes.

A sleeve half an inch long, a loose jacket waist or an unhemmed trouser is work for the tailor. Wrong shoulders, chest or jacket length mean the wrong size.

Common questions