Belt Length Calculator
Work out the strap length to cut for a belt, from the waist measurement, the buckle and the tip you want.
A belt is not the length of the waist. It is longer, because it has to pass through the buckle, double back and leave a tail, and the amount you add depends on the buckle and on how much tip the wearer likes hanging past the keeper. This calculator gives the strap length to cut, the length to the centre hole and the hole spacing, so a belt arrives the right length the first time.
At a glance
- What you enter
- Waist measurement, Ease, Buckle type, Extra tip beyond the last hole, Number of holes, Hole spacing, Belt width, Leather thickness
- What you get
- Belt size, fold to centre hole, Strap length to cut, Strap length to cut, Centre hole from the buckle fold, Centre hole from the buckle fold, First hole from the buckle fold, Last hole from the buckle fold, Tightest waist this belt fits, Loosest waist this belt fits, Adjustment range, Leather from the centre hole to the tip, Holes to punch, Leather beyond the last hole, Buckle frame clearance, Belt width, The buckle allowance pushed the first hole out
- Formula shown
- Yes, every step, right below your results.
- Cost and privacy
- Free, no account needed, and nothing you type is stored.
See worked examples ↓ Read the FAQ ↓ Share this calculator ↓
Results are estimates for general information only, always verify with a professional or official source before acting on them.
How to use the Belt Length Calculator
- 1 Enter Waist measurement (in), Measured over the trousers or the layer the belt will be worn on, not against the skin.
- 2 Enter Ease (in), The comfortable overlap between the buckle and the strap. Two inches is usual, three for a heavy belt.
- 3 Enter Buckle type
- 4 Enter Extra tip beyond the last hole (in), The tail hanging past the keeper. Four to six inches is normal for a jeans belt.
- 5 Enter Number of holes
- 6 Enter Hole spacing (in), One inch is the traditional spacing, giving two inches of adjustment either side of the centre.
- 7 Enter Belt width (in), Measure the inside of the buckle frame, not the outside.
- 8 Enter Leather thickness (mm), A thick strap takes up space inside the buckle, so a wide strap plus a thick leather may not thread.
- 9 Press Calculate. You get Belt size, fold to centre hole, Strap length to cut, Strap length to cut, Centre hole from the buckle fold, Centre hole from the buckle fold, First hole from the buckle fold, Last hole from the buckle fold, Tightest waist this belt fits, Loosest waist this belt fits, Adjustment range, Leather from the centre hole to the tip, Holes to punch, Leather beyond the last hole, Buckle frame clearance, Belt width, The buckle allowance pushed the first hole out, and every intermediate step stays visible under "How is this calculated?"
- 10 Change one number at a time to see what moves the result, that is usually the most useful thing a calculator can tell you.
Worked examples
Real numbers run through this calculator. Open any example to load it into the form above and change it.
A 34 inch waist, single prong buckle
The standard jeans belt with five holes and a five inch tip.
You enter
- Waist measurement
- 34 in
- Ease
- 2 in
- Buckle type
- 1
- Extra tip beyond the last hole
- 5 in
- Number of holes
- 5
- Hole spacing
- 1 in
- Belt width
- 1.50 in
- Leather thickness
- 4 mm
You get
- Belt size, fold to centre hole
- 36.00 in
- Strap length to cut
- 43.00 in
- Strap length to cut
- 109.22 cm
- Centre hole from the buckle fold
- 36.00 in
- Centre hole from the buckle fold
- 91.44 cm
- First hole from the buckle fold
- 34.00 in
- Last hole from the buckle fold
- 38.00 in
- Tightest waist this belt fits
- 32.00 in
- Loosest waist this belt fits
- 36.00 in
- Adjustment range
- 4.00 in
- Leather from the centre hole to the tip
- 7.00 in
- Holes to punch
- 5
- Leather beyond the last hole
- 5.00 in
- Buckle frame clearance
- 1.34 in
- Belt width
- 38.10 mm
- The buckle allowance pushed the first hole out
- 0
A size 36 belt, a strap of about 45 inches, and a centre hole 38 inches from the fold once the buckle allowance has pushed the first hole out.
A 40 inch waist, double prong buckle
A heavier belt with a double prong buckle and a longer tip.
You enter
- Waist measurement
- 40 in
- Ease
- 2.50 in
- Buckle type
- 2
- Extra tip beyond the last hole
- 6 in
- Number of holes
- 5
- Hole spacing
- 1 in
- Belt width
- 1.75 in
- Leather thickness
- 5 mm
You get
- Belt size, fold to centre hole
- 42.50 in
- Strap length to cut
- 50.50 in
- Strap length to cut
- 128.27 cm
- Centre hole from the buckle fold
- 42.50 in
- Centre hole from the buckle fold
- 107.95 cm
- First hole from the buckle fold
- 40.50 in
- Last hole from the buckle fold
- 44.50 in
- Tightest waist this belt fits
- 38.00 in
- Loosest waist this belt fits
- 42.00 in
- Adjustment range
- 4.00 in
- Leather from the centre hole to the tip
- 8.00 in
- Holes to punch
- 5
- Leather beyond the last hole
- 6.00 in
- Buckle frame clearance
- 1.55 in
- Belt width
- 44.45 mm
- The buckle allowance pushed the first hole out
- 0
A size 42.5 belt and a strap of about 52 inches, which is a long piece of leather and worth laying out on the hide before cutting.
A dress belt with a plate buckle
A 30 inch waist and a small plate buckle that the strap does not fold through.
You enter
- Waist measurement
- 30 in
- Ease
- 1.50 in
- Buckle type
- 3
- Extra tip beyond the last hole
- 4 in
- Number of holes
- 5
- Hole spacing
- 0.75 in
- Belt width
- 1 in
- Leather thickness
- 3 mm
You get
- Belt size, fold to centre hole
- 31.50 in
- Strap length to cut
- 37.00 in
- Strap length to cut
- 93.98 cm
- Centre hole from the buckle fold
- 31.50 in
- Centre hole from the buckle fold
- 80.01 cm
- First hole from the buckle fold
- 30.00 in
- Last hole from the buckle fold
- 33.00 in
- Tightest waist this belt fits
- 28.50 in
- Loosest waist this belt fits
- 31.50 in
- Adjustment range
- 3.00 in
- Leather from the centre hole to the tip
- 5.50 in
- Holes to punch
- 5
- Leather beyond the last hole
- 4.00 in
- Buckle frame clearance
- 0.88 in
- Belt width
- 25.40 mm
- The buckle allowance pushed the first hole out
- 0
A size 31.5 belt and a strap of about 39 inches. The plate buckle leaves the hole span centred, because it needs much less room.
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Frequently asked questions
How long should a belt be for a 34 inch waist?
The belt size is 36 inches, which is the measurement from the fold at the buckle to the centre hole, and that is the figure to look for on a shop label. The strap you cut is longer than that, because it also carries the remaining holes and the tail: with five holes at one inch spacing, two inches of ease and a five inch tip, the strap is about 45 inches from fold to tip. A 34 inch waist is a size 36 belt, which is why a belt is normally bought two sizes above the trouser waist.
Is a belt size the same as a waist size?
No, and this is the most common sizing mistake. A belt size is the measurement from the fold at the buckle to the centre hole, which is the wearer measurement plus the ease, so a 34 inch waist takes a size 36 belt. Trouser sizes are also vanity sized, so a 34 inch trouser usually measures more than 34 inches around the waistband. The reliable method is to measure a belt the wearer already has, from the fold to the hole they actually use, and cut to that measurement.
How many holes should a belt have?
Five holes at one inch spacing is the traditional arrangement and gives two inches of adjustment either side of the centre. Some makers cut seven for a growing teenager or for a belt that might be worn at different heights. The holes should be positioned so the wearer uses the middle one, which means the belt can go tighter and looser as the seasons change and as the leather stretches.
How much tip should hang past the last hole?
Four to six inches is the usual range for a jeans belt, with five as a good default. Below four inches the tip barely clears the keeper and looks mean; above seven and the tail hangs untidily, especially on a slimmer wearer. If the belt is a dress belt worn with a buckle and a keeper, four inches is plenty. Measure an existing belt the wearer likes and copy the tail length rather than guessing.
Does the buckle allowance change with the buckle?
Yes, and it is worth measuring the buckle in your hand. A single prong rectangular frame needs about four inches from the fold to the first hole, because the strap passes through the frame and folds back. A plate or snap buckle needs only about an inch and a half because the strap does not fold through the frame. A western buckle can need five inches or more. Where the buckle allowance is large it pushes the first hole further from the fold than a centred hole span would put it, and this calculator reports when that has happened.