How to measure
1) Measure an existing belt.
This is the best way to measure for a new belt, lay your existing belt flat on a table try to get it as straight as possible and measure from the buckle, where the leather turns, to the hole you currently wear it on (as in the figure below). The current hole you use is normally the one that shows the most wear. If you’re unsure put the belt on and fasten it so it is comfortable, take note of which hole it is fastened on, remove the belt and measure from the buckle to this hole.
If your belt is of a thin material please add 1/2” to the measurement.