Belt size calculator: waist to belt size
The belt size on a label is not your trouser size. This belt size calculator turns your waist or trouser size into the belt size to buy, in US and UK inches and in European centimetres, and shows the range the five holes cover. If you already own a belt that fits, measure it and the tool works backwards.
Use the “Allowance added” menu for a thick belt or a relaxed fit, and the chart for neighbouring sizes. Nothing is stored or sent anywhere; the sums run in your browser.
How to use the Belt Size Calculator
- Choose My waist / trouser size or A belt I own, and your units.
- Type the waist measured where the belt will sit, or the size printed on your trousers.
- Keep the standard 2 in allowance, or choose 3 or 4 in.
- Read your belt size and the European equivalent, then check the highlighted row of the chart.
- If you know a belt that fits, measure from the inner edge of the buckle to the hole you use most to get the same answer.
Belt Size Calculator features
US, UK and EU sizes
Inches for US and UK; centimetres in 5 cm steps for Europe.
Hole range
The five holes, about an inch apart, cover two inches either side of the middle hole.
Both directions
Waist to belt, or an existing belt back to a trouser size.
Chart
Even sizes from 28 to 50, with the trouser waist each suits.
The rule: waist plus two inches
Belt makers and style guides (Dalgado, Buffalo Bill Billfold Company and Swole Panda, read 19 October 2026) agree on a simple rule: buy a belt about two inches larger than your trouser waist, so a 34 in waist takes a size 36 belt. Some advise adding two to four inches, because a waist measurement only covers the body and not the thickness of the trousers or the folded tail of the belt. The belt size is measured from the inner edge of the buckle, where the prong sits, to the middle of five holes.
This tool rounds up to the next even inch, because most belts are sold in even sizes. That rounding and the one-inch spacing of the holes are this page’s assumptions; check your own belt. European belts are labelled in centimetres in steps of 5, so size 36 (91.4 cm) is shown as EU 90.
| Trouser waist | US / UK belt size | EU belt size |
|---|---|---|
| 30 in (76 cm) | 32 | 80 |
| 32 in (81 cm) | 34 | 85 |
| 34 in (86 cm) | 36 | 90 |
| 36 in (91 cm) | 38 | 95 |
| 38 in (97 cm) | 40 | 100 |
| 40 in (102 cm) | 42 | 105 |
Limits
Brands differ: one maker may size a belt a full inch generous, another may label the overall length instead of the buckle-to-hole distance, and low-rise or high-rise trousers move the belt line. Women’s belts are often sold as S, M and L, with sizes that vary by brand; use the waist figure with the brand’s chart. If you are between sizes, choose the larger, and check the holes you will actually use. For trousers and shirts see the clothing size converter and the length converter.
Belt Size Calculator FAQ
What size belt do I need for a 34 inch waist?
Usually a size 36 (about 90 cm in Europe): add 2 inches to the waist. Its holes fit waists from about 34 to 38 inches.
How do I measure my belt size?
Lay a belt flat and measure from the inner edge of the buckle, where the prong sits, to the hole you use most. That length is your belt size.
Is belt size the same as trouser size?
No. Belts are normally sized about two inches larger than the trousers, so the belt can pass through the loops and fasten.
What is the European belt size for a 36 belt?
About 90 cm. European belts come in 5 cm steps (85, 90, 95, 100, …).
Should I size up if I am between sizes?
Yes, take the larger size; a belt with spare holes can always be used on a tighter hole, but a belt that is too short cannot be extended.
Does it work for women’s belts?
The same waist-plus-two-inches idea applies, but women’s belts are often S, M or L and vary by brand, so use the brand’s chart too.