Jacket Size Calculator — Men's Suit & Coat Size
Enter your chest circumference and sleeve length to get your jacket size across US/UK, EU, Italian and French sizing standards — instantly, with slim, regular or relaxed fit adjustment.
in
Unit
in
Preferred fit
How does this calculator work?
US/UK jacket size = chest in inches (even), plus S/R/L sleeve letter. EU = chest in cm (even). IT = EU + 12, FR = EU + 14. A 40-inch chest with 32-inch sleeve = US 40R, EU 102, IT 114, FR 116. Slim fit sizes up by one; relaxed sizes down by one.
Formula
How this is calculated
Men’s jacket sizing in the US and UK is driven primarily by chest circumference measured in inches. Manufacturers round to the nearest even number (34, 36, 38, …) and append a sleeve-length letter: S (Short, up to 30 in), R (Regular, 31–33 in) or L (Long, 34 in+). A size labelled "40R" means a 40-inch chest in a regular sleeve length.
European sizing uses chest in centimetres rounded to the nearest even number — a 40-inch chest is roughly 102 cm, so the EU size is approximately 102. Italian sizes add 12 to the EU number (making it 114) while French sizes add 14 (making it 116). These offsets are conventional across most major brands but can vary slightly.
Fit preference shifts the recommendation: a slim-fit jacket in your chest size will have a more tapered waist and less chest room, while a relaxed or comfort-fit jacket adds room throughout. If you are between sizes, slim-fit buyers generally size up one size and regular-fit buyers take their standard size. Always try before you buy — brands differ in how they interpret "regular" proportions.
Frequently asked questions
Wrap a flexible tape measure around the fullest part of your chest (usually across the nipple line), keeping it level and snug but not tight. Breathe normally. Measure in inches for US/UK sizing or centimetres for EU sizing.
They refer to the sleeve/body length: S (Short) suits men around 5'5″–5'8″, R (Regular) suits 5'9″–6'1″, and L (Long) suits 6'2″ and taller. The chest number in the size stays the same regardless of the letter.
No. A US/UK 40 means a 40-inch chest (≈ 102 cm). The EU equivalent is about 102, not 40. EU and US numbers use completely different scales, which is why this calculator converts between them.
Also known as
TG we-Calculate Editorial Team. (2026). Jacket Size Calculator — Men's Suit & Coat Size [Online calculator]. TG we-Calculate. https://we-calculate.com/calculator/jacket-size-calculator
TG we-Calculate Editorial Team. "Jacket Size Calculator — Men's Suit & Coat Size." TG we-Calculate. 2026. https://we-calculate.com/calculator/jacket-size-calculator.
TG we-Calculate Editorial Team, "Jacket Size Calculator — Men's Suit & Coat Size," TG we-Calculate, 2026. [Online]. Available: https://we-calculate.com/calculator/jacket-size-calculator
@misc{wecalculate_jacket_size_calculator, title = {Jacket Size Calculator — Men's Suit & Coat Size}, author = {{TG we-Calculate Editorial Team}}, howpublished = {\url{https://we-calculate.com/calculator/jacket-size-calculator}}, year = {2026}, note = {TG we-Calculate} }
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