Belt sizes are measured from where the leather folds at the buckle to the middle hole, so a belt labelled 36 fits a 34 in trouser waist with room to adjust either way. Measuring a belt that already fits is the most reliable method.
How to use the Belt Size Calculator
- I know my
- Measurement
Results update as you type, and every field accepts the units shown in its menu.
How it works
Choose what you know – your waist circumference, your trouser size or the length of a belt that fits – and enter it.
Belt size chart
| Trouser waist | Belt size | Letter |
|---|---|---|
| 28–30 in | 30–32 | XS |
| 30–32 in | 32–34 | S |
| 34–36 in | 36–38 | M |
| 38–40 in | 40–42 | L |
| 42–44 in | 44–46 | XL |
| 46–48 in | 48–50 | 2XL |
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 |
|---|---|
| I know my | Choose one: Waist circumference (measured), Trouser / jeans waist size, Old belt: buckle fold to the hole I use |
| Measurement | Units: in, cm |
What each result means
- European size (cm) = round([Belt size]÷0.05)×5
- Approximate overall belt length = [Belt size] + 5.5×0.0254
Formula
Belt size = trouser waist size + 2 in (5 cm)Belt size from an old belt = length from the buckle fold to the hole you useTotal belt length ≈ belt size + 5–6 in for the buckle and tipWorked example
Inputs — I know my: Trouser / jeans waist size; Measurement: 34 in.
Results — Belt size = 36 in; European size (cm) = 90; Letter size = M; Approximate overall belt length = 41 in.
Frequently asked questions
What size belt for 34 waist jeans?
A size 36 belt.
How do I measure a belt?
Measure from the fold where the buckle attaches to the hole you use most.
What if I am between sizes?
Choose the larger size – you can always use a tighter hole.
What formula does the Belt Size Calculator use?
Belt size = trouser waist size + 2 in (5 cm).