Blazer Size Chart: Numbers, Letters and Length Codes Explained

Men's blazer size chart

Each blazer size covers one even-numbered chest in inches. The letter equivalents are how the same chest is labeled on casual jackets and knitwear, which is useful when a brand only sells blazers in S, M and L.

German and some Austrian and Swiss brands use three parallel scales. Regular sizes (Normalgrößen) match the EU column. Short, fuller-build sizes (untersetzte Größen) are half the regular number: 25 is a short 50. Long, slim sizes (schlanke Größen) are roughly double the regular number minus 2: 98 is a long 50. Odd sizes such as 39R or 41L appear only from a few makers and fill the 1 in gaps.

What S, R and L mean on a blazer

The letter after the number sets the jacket's back length and sleeve length; the chest stays the same. A 40S and a 40L fit the same chest, but the 40L is about 2 to 3 in (5 to 8 cm) longer in body and sleeve.

Height is only a proxy for arm and torso length. A man of 5 ft 11 in with long arms may need a long; check the sleeve before deciding.

Blazer length by height

A traditional tailoring rule sets jacket length at half the distance from the base of the collar to the floor. With average proportions that is about 43% of height, which gives these back lengths:

Two quick checks confirm it in a fitting room: the jacket should cover the seat, and with arms hanging relaxed, the hem should reach about the middle of the hand, around the knuckles of a slightly cupped fist.

Women's blazer sizes

Women's blazers use dress sizes, so they convert like other women's clothing. Fit is decided at the shoulders and bust; the waist is the easiest part for a tailor to adjust.

A women's blazer labeled 36 or 38 is a European dress size, not a chest in inches: a 36 is a US 4 to 6. Women buying men's blazers for an oversized look should convert by bust: a women's M (35-37 in bust) corresponds to a men's 36 or 38, but the men's jacket will be broader in the shoulders and longer in the sleeve.

How a blazer should fit

1. Shoulders. The shoulder seam ends at the edge of your shoulder bone, with the sleeve hanging straight. A dent below the shoulder pad means the jacket is too big; a pulled sleeve head means too small. Choose by shoulders, because they are the hardest part to alter.
2. Chest and button. Buttoned (top button on a two-button, middle on a three-button), the front lies flat. An X-shaped crease around the button means it is too tight.
3. Collar. The jacket collar rests against the shirt collar at the back with no gap, and about 0.5 in (1 cm) of shirt collar shows above it.
4. Sleeves. With arms relaxed, 0.25 to 0.5 in (6 to 13 mm) of shirt cuff shows below the blazer sleeve. Sleeves are the easiest length to alter, typically by up to about 1 to 1.5 in either way depending on the cuff construction.
5. Length. Covers the seat; see the length table above.

The shirt underneath matters for that sleeve check; the shirt size chart covers sleeve lengths. A blazer bought as part of a matching set, with trousers in a fixed drop, is covered in the suit size guide, and a matching waistcoat in the vest size guide.

Blazer, sport coat and suit jacket: is the sizing the same?

• Suit jackets are sold with matching trousers and are cut closest, for wear over a shirt.
• Blazers (solid color, often navy, sometimes with metal buttons) use the same size labels and usually the same pattern as the maker's suit jackets.
• Sport coats (patterned or textured cloth such as tweed) are often cut with slightly more room to fit over a thin knit. If you are between sizes, a sport coat is the one to take in the smaller size.

Unstructured or knit blazers have soft shoulders and some stretch; they forgive a size that is slightly small but not one that is too big in the shoulders. For an overcoat to wear on top, see the coat size guide; for casual outerwear, the jacket size guide.

Frequently asked questions