Sandpaper Grit Calculator — Quantities

This tool builds a fine progression that never skips a grade — for standard furniture (start 80, finish 220) that is 80 → 100 → 120 → 150 → 180 → 220, six grits. You can sand faster with the classic 80 → 120 → 180 → 220 if you prefer, since each of those jumps still stays under the "don't more than double" rule, but the gentler full sequence leaves the cleanest surface. For ultra-smooth finishes the sequence continues to 320 (and 400 on hardwood); for rough timber it starts at 60. Never skip more than one grit step.

Roughly one sheet covers 2 m² before wearing out. Coarser grits wear faster in hardwood. Sand with the grain and replace sheets when they stop cutting efficiently.

Always use a sanding block for flat surfaces — hand sanding without a block creates uneven pressure and dips. Use flexible pads for curves. Cork blocks are gentler than hard rubber.