Belt Blank Calculator
How long to cut a leather belt strap for your size, where to punch the holes, and how many belts a side of leather gives.
Result
Strap length to cut: 46 inEstimate
The fold and tip allowances are conventions: change them to suit your buckle and tip shape.
- Centre hole from the buckle end
- 39 in
- Hole nearest the buckle, from the buckle end
- 37 in
- Hole nearest the tip, from the buckle end
- 41 in
- Belt size used
- 36 in
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How to use the Belt Blank Calculator
- Measure a belt that fits from the fold at the buckle to the hole you use, or enter your trouser waist and what to add.
- Choose the number of holes and their spacing.
- Check the fold allowance at the buckle and the length of the tip beyond the last hole.
- Read the strap length to cut and where to punch each hole, measured from the buckle end.
How it is calculated
centre hole = fold allowance + belt size (from the buckle end of the strap)holes = centre hole ± spacing, (holes − 1) ÷ 2 each waycut length = centre hole + (holes − 1) ÷ 2 × spacing + tipbelts = ⌊usable width ÷ strap width⌋ × ⌊usable length ÷ cut length⌋The centre hole sits exactly one belt size from the fold, so a belt made to your measurement fits on its middle hole with room either way. Buckle My Belt measures belts this way and puts five holes an inch apart.
Conventions you can change
The 3 inch fold and the 5 inches from the last hole to the tip are the figures in Gold Bark Leather’s DIY belt guide; the metric defaults of 7.5 and 12.5 cm are those rounded. A wide buckle, a snap or Chicago screw closure, or a longer keeper all change the fold allowance, and a round or English point changes the tip. Mark your own buckle end on a scrap to check before cutting good leather.
What is not included
The page does not size the buckle slot, the keeper or the edge finish, and makes no allowance for the shape of the side or its flaws when counting belts. Hand stitching the keeper or a folded buckle end uses thread; the saddle stitch thread calculator works out how much.
With your numbers
- Centre hole = 3 in + 36 in = 39 in from the buckle end
- Holes from 37 in to 41 in, 1 in apart
- Strap = 41 in + 5 in = 46 in
Quick reference
The fold and tip allowances are conventions: change them to suit your buckle and tip shape.
| Example | Strap length to cut |
|---|---|
| 36 in belt, 5 holes | 46 in |
| 34 in waist, add 2 in | 46 in |
| 42 in belt, 7 holes 1 1/4 in apart | 52 3/4 in |
| 36 in belt, 60 × 20 in side, 1 1/2 in strap | 46 in |
| 90 cm belt, 5 holes | 115 cm |
| 90 cm belt, 250 × 55 cm side, 4 cm strap | 115 cm |
| 100 cm belt, 3 holes | 122.5 cm |
Common questions about the Belt Blank Calculator
- How long should I cut a leather belt?
- The belt size, plus the leather that folds round the buckle, plus the holes beyond the centre and the tip. For a 36 inch belt with a 3 inch fold, five holes an inch apart and 5 inches from the last hole to the tip, that is 3 + 36 + 2 + 5, or 46 inches.
- How is belt size measured?
- From the fold where the leather wraps round the buckle bar to the hole you use most, which becomes the centre hole. It is not the full length of the strap, and it is usually a little more than your trouser waist size because the belt goes round the trousers.
- What if I only know my waist size?
- Add a margin for the belt going over clothing. Buckle My Belt suggests 2 to 3 inches over a trouser waist size and 3 to 5 inches for jeans. A belt that already fits is the more reliable measure.
- How many belts can I cut from a side of leather?
- Count the straps that fit across the usable width, then how many belt lengths fit in each strap along the usable length. A usable strip 60 inches long gives one 46 inch strap, so a side 20 inches wide at 1 1/2 inch straps gives 13 belts. Sides are irregular and have flaws, so measure the leather you have.