OneTaskBy Tim King · Updated
Belt Size Calculator
Belt Size From Waist or an Old Belt, in Inches and cm
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How the Belt Size Calculator works
This belt size calculator gives the belt size to order from either your trouser waist size or an old belt that fits. For an old belt, measure from where the strap leaves the buckle to the hole you use most. Enter inches or centimetres and you get the size in both, the letter size and the rough overall length of the belt.
A belt has to go around the waistband of your trousers, not just your body, so it is sized a little larger than the waist number on your jeans. Belt sizes are measured from the buckle to the middle hole, which leaves two holes of adjustment either way. European belts are labelled in centimetres, usually in steps of 5.
How the belt size calculator works
The formula from a trouser waist is belt size = waist + 2 in, the usual allowance for the waistband and for the belt sitting over it. From an old belt, the buckle-to-favourite-hole length is the belt size. The centimetre size is rounded to the nearest 5 cm, and the overall length of the strap is roughly the belt size plus 5 to 7 in for the buckle and the tail.
First example. Trousers with a W34 waist need a size 36 belt, which is a 90 cm belt in European sizing and a size L. The strap is about 41 to 43 in long overall.
Second example. An old belt measures 95 cm from the buckle to the favourite hole. That is 37.4 in, so the belt size is 37 in, it suits a W35 waist and the letter size is L.
How many inches bigger than the waist? Two inches, or about 5 cm, for most belts. Wide casual belts worn over thick denim may need 3 in, and thin dress belts on trim trousers can take 1 in.
Trouser waist sizes with the belt size in inches and centimetres
| Trouser waist | Belt size (in) | Belt size (cm) | Letter |
|---|---|---|---|
| W26 | 28 in | 70 cm | S |
| W27 | 29 in | 75 cm | S |
| W28 | 30 in | 75 cm | S |
| W29 | 31 in | 80 cm | S |
| W30 | 32 in | 80 cm | M |
| W31 | 33 in | 85 cm | M |
| W32 | 34 in | 85 cm | M |
| W33 | 35 in | 90 cm | M |
| W34 | 36 in | 90 cm | L |
| W35 | 37 in | 95 cm | L |
| W36 | 38 in | 95 cm | L |
| W37 | 39 in | 100 cm | L |
| W38 | 40 in | 100 cm | XL |
| W39 | 41 in | 105 cm | XL |
| W40 | 42 in | 105 cm | XL |
| W41 | 43 in | 110 cm | XL |
| W42 | 44 in | 110 cm | XXL |
| W43 | 45 in | 115 cm | XXL |
| W44 | 46 in | 115 cm | XXL |
| W45 | 47 in | 120 cm | XXL |
| W46 | 48 in | 120 cm | 3XL |
| W47 | 49 in | 125 cm | 3XL |
| W48 | 50 in | 125 cm | 3XL |
| W49 | 51 in | 130 cm | 3XL |
| W50 | 52 in | 130 cm | 3XL |
Tips and pitfalls
- Do not measure the full strap. The overall length includes the buckle and tail, so it reads 5 to 7 in bigger than the size.
- Measure from the buckle fold. Start where the leather leaves the buckle, not from the end of the buckle frame.
- Between sizes, go up. A belt can always be shortened or have a hole added; a short one cannot be fixed.
- Waist labels can be generous. If your jeans run large, measure your actual waist over your trousers instead of using the label.
FAQ
How do I work out my belt size?
Add 2 inches to your trouser waist size, so W32 trousers need a size 34 belt. Or take a belt that fits and measure from where the strap leaves the buckle to the hole you use most. That length is your belt size.
What size belt for a 34 waist?
A 34-inch waist needs a size 36 belt, which is about 90 cm in European sizing. That is usually sold as a large. If you wear the belt over thick denim, a 37 or 38 can be more comfortable.
What are belt sizes in centimetres?
European belts are labelled in centimetres from the buckle to the middle hole, usually in steps of 5: 85, 90, 95, 100 and so on. Divide by 2.54 to compare with inch sizes; 90 cm is about 35.5 in.
What do S, M, L belt sizes mean?
Letter sizes are ranges, usually S for 28 to 32 in, M for 32 to 36 in, L for 36 to 40 in and XL for 40 to 44 in belt sizes. Brands differ slightly, so check the inch or centimetre figure where one is given.
How many holes should a belt have?
Most belts have five holes about 1 in apart, with the size measured to the middle hole. That gives two holes of adjustment either way, so the favourite hole should ideally be the third.
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