How to measure a sanding belt

Record sizes as width × length (full loop circumference). Choose a method below.

Method 1Fold & Measure (fastest)
1
Lay the old belt flat and fold once to make a double layer.
2
Align the splice at one end and the fold at the other; measure splice → fold.
3
Double that value for the total loop length (circumference).
4
Measure width; record as width × length.
If the belt is split, cut it once and measure end-to-end — that equals the loop length.

Method 2String Method (no tape measure)
1
Route a piece of string along the exact belt path (tension released).
2
Mark where the string meets; cut or hold the mark.
3
Lay it flat and measure — that’s your loop length.
4
Measure and note the width.

Helpful notes

  • Tolerance: If you’re within a few mm of a standard length, round to the nearest common size.
  • Common lengths (mm): 915, 1000, 1220, 1320, 2000 (others available).
  • Metric ⇆ Imperial: 1″ = 25.4 mm. Example: 2″ ≈ 50.8 mm.
  • Record format: always width × length, e.g. 50 mm × 2000 mm.
  • Width tip: If you don’t have the old belt, read the contact wheel width or the machine’s spec plate.
Ordering checklist: width × length, grit, quantity, and application (e.g. stainless steel, hardwood). If unsure, tell us your material and finish goal—we’ll advise the best belt type.

Popular sizes (quick reference)

WidthCommon LengthsNotes
10–13 mm330, 457, 610Finger files / narrow arm sanders
25–50 mm915, 1000, 1220, 1320Bench sanders / Dynafile types
75–100 mm2000+Larger linishers & belt grinders

FAQ

My belt snapped — can I still measure it?
Yes. Cut it once to create a straight strip and measure end-to-end for the loop length; measure width as normal.
What if the machine has auto-tension?
Release tension before measuring (string or tape). Auto-tension can add length if left engaged.