Men’s jackets are sold by chest size in inches with a length code, so a 40R fits a 40 in chest on someone of average height. European sizes are half the chest in centimetres (40 in ≈ 50). Women’s jackets follow dress sizes, and when bust and hips fall in different sizes the larger one should usually be chosen.
How to use the Jacket Size Calculator
- Sizing
- Chest / bust
- Height
- Hips
Results update as you type, and every field accepts the units shown in its menu.
How it works
Choose men’s or women’s sizing, then measure the chest (or bust) at the fullest part with arms relaxed, plus height (men) or hips (women).
Tips
- Measure over thin clothing with a soft tape held snug but not tight, and keep the tape level all the way round.
- Take each measurement twice; if you are between sizes, the larger size is usually the safer choice.
- Size charts vary by brand and country – check the maker’s own chart when it is available.
- For sewing projects, pre-wash fabric before cutting and buy 10% extra for shrinkage, pattern matching and mistakes.
Common mistakes to avoid
- Mixing inches and centimetres between the tape and the size chart.
- Forgetting seam and hem allowances when cutting fabric.
- Measuring an old, stretched garment instead of your body.
Inputs explained
| Field | What to enter |
|---|---|
| Sizing | Choose one: Men’s, Women’s |
| Chest / bust | Units: in, cm |
| Height | Units: in, cm, ft |
| Hips | Units: in, cm |
What each result means
- Men’s US/UK chest size = 2×round([Chest ÷ bust]÷0.0254÷2)
- Men’s EU size = 2×round([Chest ÷ bust]÷0.01÷4)
- Women’s US size = min([Women’s size index], 12)
- Women’s EU size = min([Women’s size index], 12)
Example values
How the main result changes when Chest / bust changes and everything else stays at the example values above:
| Chest / bust (in) | Men’s US/UK chest size |
|---|---|
| 20 | 20 |
| 30 | 30 |
| 40 | 40 |
| 50 | 50 |
| 60 | 60 |
| 80 | 80 |
Formula
Men: jacket size = chest (in); length S < 5'8", R 5'8"–6'0", L > 6'0"; EU = chest (cm) ÷ 2Women: size from the larger of bust and hip on the standard chartWorked example
Inputs — Sizing: Men's; Chest / bust: 40 in; Height: 70 in; Hips: 40 in.
Results — Men's US/UK chest size = 40; Men's length = Regular (R); Men's EU size = 50; Men's letter size = M; Women's US size = 14; Women's EU size = 44.
Frequently asked questions
What does 40R mean?
A 40 in chest with regular length, for men roughly 5'8"–6'0" tall.
How do I convert US jacket size to EU?
Add 10 for men: US 40 = EU 50.
Should a jacket be my exact chest size?
Yes – the jacket size already includes the ease for movement.
What formula does the Jacket Size Calculator use?
Men: jacket size = chest (in); length S < 5'8", R 5'8"–6'0", L > 6'0"; EU = chest (cm) ÷ 2.