Leather Belt Blank Size Calculator
Created by: Natalie Reed
Last updated:
Calculate the exact belt blank length, width, and hole positions from waist size. Choose your buckle type, number of holes, and tip style — get a complete cutting specification with visual layout diagram.
Belt Blank Size Calculator
LeathercraftCalculate belt blank dimensions and hole positions from waist size
Waist & Style
Buckle & Holes
Tip Style
Related Calculators
What is a Leather Belt Blank Size Calculator?
A Belt Blank Size Calculator determines the exact length and width of leather you need to cut for a belt based on the wearer's waist size, buckle style, and desired hole pattern. It eliminates guesswork by calculating the fold-back allowance, tongue extension, and precise hole positions.
Getting belt sizing wrong wastes expensive leather. Cut too short and the belt won't buckle; cut too long and it wraps awkwardly. This calculator ensures every belt fits perfectly on the first cut, whether you're making a single custom belt or a batch for retail.
Belt Blank Formulas
Fold-back allowance: Leather that wraps around the buckle bar — typically 3-4 inches for snap attachment, 2-3 inches for chicago screws.
Tongue extension: Leather past the centre hole to the tip — typically 4-5 inches past the last hole.
Blank length: Fold-back + Waist size + Tongue extension
Centre hole position: Fold-back + Waist size (from the buckle end)
Hole spacing: Standard 1" apart, centred on the centre hole
Standard Belt Size Reference
| Waist Size | Trouser Size | Belt Size (to centre hole) | Blank Length (approx) |
|---|---|---|---|
| 28" | 26" | 28" | 38" |
| 30" | 28" | 30" | 40" |
| 32" | 30" | 32" | 42" |
| 34" | 32" | 34" | 44" |
| 36" | 34" | 36" | 46" |
| 38" | 36" | 38" | 48" |
| 40" | 38" | 40" | 50" |
| 42" | 40" | 42" | 52" |
| 44" | 42" | 44" | 54" |
Belt Making Tips
- Always cut the belt blank 1-2 inches longer than calculated — you can trim the tip but cannot add length.
- Use a belt-hole punch (not a rotary punch) for clean, uniform holes that won't tear.
- Standard hole size is 1/8" for dress belts and 5/32" for casual belts to match common prong sizes.
- Round or point the belt tip using a template for a professional finish.
- Edge and burnish the belt blank before assembly — it's much easier on a flat strap than a finished belt.
- For snap-on buckle belts, use heavy-duty line 24 snaps spaced 3/4" apart on the fold-back.
Frequently Asked Questions
How do I determine the correct belt blank length?
Start with the wearer's waist size, then add 8-10 inches for the fold-back at the buckle end (typically 3"), the tongue past the buckle prong hole (1-2"), and extra length beyond the keeper (4-5"). For example, a 34" waist needs a belt blank roughly 42-44" long. This calculator factors in all these additions automatically.
Where should belt holes be placed?
The centre hole (third of five) should align with the wearer's waist measurement. Holes are spaced 1 inch apart. So for a 34" waist, the centre hole is at 34" from the fold, with holes at 32", 33", 34", 35", and 36". Standard belts have 5 holes, but you can add 7 for more adjustability.
What width should a leather belt be?
Dress belts are typically 1" to 1.25" wide. Casual belts are 1.25" to 1.5". Work/utility belts are 1.5" to 1.75". Gun belts and tool belts are 1.5" to 2". The width must match the buckle's bar width and fit through the wearer's belt loops (most jeans accommodate up to 1.75").
What leather thickness is best for belts?
Belt straps should be 8-10 oz (3.2-4.0 mm) for dress belts and 9-11 oz (3.6-4.4 mm) for casual/work belts. Gun belts need 12-14 oz (4.8-5.6 mm) for rigidity. Thinner leather (6-7 oz) can work for women's fashion belts. Veg-tanned leather is preferred because it holds its shape better than chrome-tanned.
How do I size a belt for someone without their waist measurement?
If they have an existing belt, measure from the fold (or where the leather meets the buckle) to the most-used hole. Alternatively, measure their trouser waist size and add 2 inches. A size 34 trouser usually wears a 36" belt. This calculator supports both methods.
Sources and References
- Tandy Leather, "Belt Making Guide and Sizing Chart", 2024
- Ian Atkinson / Leodis Leather, "Belt Making Masterclass", 2024
- r/Leathercraft Community, "Belt Sizing FAQ and Common Mistakes", 2024