Free stack builder for inch and metric gage (gauge) block sets
Gage blocks (also called gauge blocks or slip gauges) wring together into a precise length. This calculator uses the classic digit-by-digit method machinists learn in the shop: clear the rightmost digits first so you use as few blocks as possible.
Works offline as an installable app. Built for toolrooms, QC, and hobby CNC.
An 81-piece inch rectangular set (Mitutoyo / Starrett style) covers most shop work in 0.0001" steps. A 36-piece kit is lighter for coarser targets; 28-piece thin sets fill tiny steps. Metric shops usually start with 112 or 88 pieces. Pick your set above, build stacks here for free, then use the shop links if you need to buy one.
Sacrificial end blocks (commonly 2×0.050" or 2×1 mm) wrung on the outside of a stack so contact wear hits them instead of your precision set. Turn on the wear toggle so the calculator includes them in the total.
A serrated gage block stone knocks down light nicks and burrs so blocks wring again. Keep it clean — grit on the stone can lap and change size. It does not replace badly damaged blocks.
Yes. The core stack builder stays free and ungated. Optional Amazon links may earn a commission (Amazon Associates).