Belt Blank Length Calculator
Get the blank length to cut and where to punch five holes for a belt, based on your waist measurement.
Punch holes at: 34, 35, 36, 37, 38 in (center hole = 36 in).
Measure from the fold at the buckle bar to the worn hole on an existing belt, or your waist over clothes, for the most reliable number. Punch and test the center hole first; buckle styles change the fold allowance slightly.
How it works
A belt blank needs to be longer than your waist measurement in two directions: back through the buckle, where the leather folds over the bar and gets stitched or riveted down, and forward past the hole you actually wear to the tip. The calculator adds a 3.5 in fold-back allowance and a 6 in tip allowance to your waist number, then lays out five holes an inch apart so you have room to adjust as your weight shifts a little.
Worked example: a 36 in waist. Add 3.5 in for the fold and 6 in to the tip and the blank comes out to 45.5 in. The five holes sit at 34, 35, 36, 37, and 38 in, with 36 in as the center hole, matching the waist measurement you started with.
FAQ
Should I measure my waist or an existing belt?
An existing belt is more reliable. Measure from where the leather folds at the buckle bar to the hole you actually wear, since a body waist measurement over clothes can be off by an inch or two depending on where the belt sits and how it's worn.
Why does the fold allowance change with buckle style?
A wider or a double-prong buckle needs more leather wrapped around the bar to stitch or rivet securely, which can add half an inch or more beyond the standard 3.5 in. Dry fit the buckle end on scrap before cutting your good leather if you're using an unusual buckle.
Which hole should I punch first?
Punch the center hole and try the belt on before punching the rest. It's much easier to shift the remaining four holes than to fix a blank that was cut short because the center hole landed in the wrong place.
Do I need five holes?
Five is a comfortable standard that covers normal weight fluctuation without weakening the leather with holes you'll never use. You can punch fewer if you're confident in the fit, or add a sixth further out for extra range.
For cutting and building the belt itself, see how to make a leather belt from scratch, a beginner's buying guide to buckles and hardware, and how to set rivets without wrecking them.