Jacket Size Calculator

This suit jacket size calculator turns a tape measurement into a wearable size: men's chest to US, UK and EU jacket sizes with sleeve length and fit, plus a women's sizer by bust with petite and regular bands. Not sure what is my suit jacket size? Start with your chest (men) or bust (women) below - jacket size by chest measurement and jacket size by bust measurement are each one step.

Example: a 42-inch chest with a 36-inch waist at 5 ft 11 in is a US 42 (UK 42, EU 52) - alpha L, 34.5-inch sleeves, Regular length, classic drop-6 regular fit.

Scope note: this tool covers suit jackets, blazers, sport coats and casual jackets for men and women. Sleeve lengths follow the neck-to-wrist method (center back of neck, over the shoulder, to the wrist); brands vary about ±0.5 in.

1 · Men's jacket sizer

Use this mens jacket size calculator with your chest measurement - add waist and height for fit and length code. Chest in inches equals the US jacket size.

Units

Chest (in) Waist (in) - optional, for drop & fit

Height (in) - optional, for S/R/L

2 · Women's jacket sizer

This womens jacket size calculator converts bust to a US numeric size and alpha size, with a petite or regular band from your height. That is jacket size by bust measurement, one step.

Units

Bust (in)

Height (in) - optional, for petite/regular

3 · Suit jacket specifics - length, fit & button stance

How should a suit jacket fit? Start from the numbers, then the rules of thumb below.

Jacket length code by height

Code	Height	Means
S (Short)	Under 5 ft 8 in	Shorter body & sleeves (about 1 in less)
R (Regular)	5 ft 8 in - 6 ft 2 in	Standard proportions
L (Long)	Over 6 ft 2 in	Longer body & sleeves (about 1 in more)

Drop & fit guidance

Drop = chest minus waist. The classic American block is drop 6. Drop 7+ suits slim/athletic cuts, 5-6 is regular, 4 or less suits classic/portly cuts. A tailor can take in the waist by an inch or two - chest and shoulders are the expensive alterations, so get those right first.

Suit jacket button stance guidance

1-button: fasten it; it sits at the natural waist.
2-button: fasten the top button only; it sits at or just above the natural waist.
3-button: fasten the middle (top optional, bottom never); the middle sits at the natural waist.
Double-breasted: fasten all working buttons.

Button stance is tailoring guidance, not gospel - fashion houses move it with the seasons.

4 · Jacket size chart men - US / UK / EU with sleeve

Read it as a jacket sleeve length chart too: sleeve = 24 + size/4, measured neck-to-wrist. Sizes 50-60 are a formula extension of the retail chart extension; alpha sizes are an approximate industry mapping approx.

US	UK	EU	Alpha	Chest (in)	Waist std (in)	Sleeve (in)
34	34	44	XS	34	28	32.5
36	36	46	S	36	30	33
38	38	48	M	38	32	33.5
40	40	50	M	40	34	34
42	42	52	L	42	36	34.5
44	44	54	XL	44	38	35
46	46	56	XL	46	40	35.5
48	48	58	XXL	48	42	36
50	50	60	XXL	50	44	36.5
52	52	62	3XL	52	46	37
54	54	64	3XL	54	48	37.5
56	56	66	4XL	56	50	38
58	58	68	4XL	58	52	38.5
60	60	70	5XL	60	54	39

5 · Jacket size chart women - bust to size

The womens blazer size chart below maps bust to US numeric size; sleeve is approximate and shortens about an inch in petite. Petite = 5 ft 4 in and under (some brands use 5 ft 3 in).

US	Alpha	Bust (in)	Sleeve approx (in)
0	XS	32	23.5
2	XS	33	24.5
4	S	34	24.5
6	S	35	25
8	M	36	25
10	M	37	25.5
12	L	38.5	25.5
14	L	40	26
16	XL	42	26
18	XL	44	26
20	XXL	47.5	26

6 · How to measure jacket size

Chest (men): tape around the fullest part of the chest, under the armpits and across the shoulder blades, level all round, over a shirt.
Waist: around the natural waist where trousers sit, one finger of ease.
Sleeve: bend the arm slightly; measure from the center back of the neck, over the shoulder, down to the wrist.
Bust (women): tape around the fullest part of the bust, parallel to the floor, over undergarments.
Between sizes? Size up to the next even size - taking in is cheap, letting out is not.

Frequently asked questions

What size jacket am I if my chest measures 42 inches?

A 42-inch chest is a US/UK size 42 jacket - suit jacket sizes equal the chest measurement in inches. That converts to EU 52 (us to eu jacket size conversion: add 10). Expect an alpha size of L and a regular suit jacket sleeve length of 34.5 inches; at 5 ft 11 in tall the jacket length code is Regular (R).

How do I convert a US jacket size to an EU size?

Add 10: EU = US + 10, and UK sizes match US numbers one-to-one (uk to us jacket size conversion is 1:1). So a US 40 becomes EU 50 and a US 42 becomes EU 52 - which answers the common query '42 jacket size in eu': it is 52.

What does jacket 'drop' mean?

Drop is chest size minus waist size. The classic American suit jacket uses drop 6: a 42-inch chest pairs with a 36-inch waist (42 - 36 = 6). A drop of 7 or more suggests a slim or athletic cut, 5-6 is regular, and 4 or less is a classic or portly cut. That is the short version of jacket drop size meaning.

What sleeve length should a 40R suit jacket have?

About 34 inches, measured from the center back of the neck, over the shoulder, to the wrist. Sleeve length grows roughly half an inch per two jacket sizes (sleeve = 24 + size/4, so a 40 gives 34 and a 42 gives 34.5). Short lengths run about 1 inch shorter and long about 1 inch longer - see the jacket sleeve length chart below.

What women's jacket size is a 37-inch bust?

US size 10 (M). At 5 ft 5 in you take the Regular band - petite is 5 ft 4 in and under - and the approximate blazer sleeve for that size is 25.5 inches. That is jacket size by bust measurement in one step.

What does 42L mean on a suit jacket?

42 is the chest size in inches; L is the jacket length code for Long, for heights over 6 ft 2 in. The full suit jacket length short regular long scale is: Short under 5 ft 8 in, Regular 5 ft 8 in to 6 ft 2 in, Long over 6 ft 2 in - that is jacket length by height.

How do I measure my chest for a jacket?

Stand relaxed and wrap the tape around the fullest part of your chest, under your armpits and across your shoulder blades, keeping the tape level - that is how to measure jacket size for men. Measure over a shirt, not a sweater. Then chest size to jacket size is direct: a 40-inch measurement is a size 40.

What blazer size do I need for a 38-inch chest?

US/UK 38 - a blazer size calculator men can trust gives the same answer as the suit chart because chest equals size. That is EU 48, alpha M, with a 33.5-inch sleeve. Check the mens blazer size chart below for the full row.

What is the difference between petite and regular women's jackets?

Petite cuts are for 5 ft 4 in and under, with shorter sleeves and body; Regular is above 5 ft 4 in (some brands draw the line at 5 ft 3 in). Example: a 35-inch bust at 5 ft 3 in is a size 6 Petite - this page doubles as a jacket size calculator women petite. Bust size to jacket size women works the same in both bands; only the proportions change.

Where should the buttons sit on a suit jacket?

Guidance, not gospel - tailors vary. On a 2-button jacket fasten only the top button and it should sit at or just above your natural waist; on a 3-button fasten the middle (top optional, bottom never); on a 1-button fasten it at the natural waist; on a double-breasted fasten all working buttons. That is the classic suit jacket button stance.

How do I find my jacket size in centimeters?

Divide by 2.54 first. A 100 cm chest is 39.4 inches, which rounds up to a US 40 (UK 40, EU 50). Switch the unit toggle above to cm and this jacket size calculator cm handles the conversion for you.

Should I size up if I am between jacket sizes?

Yes - size up to the next even size. A 39-inch chest rounds up to a 40, not down to 38, because a tailor can take a jacket in but cannot add fabric to the chest. Useful whenever you ask what size jacket am i and land between two numbers.