WoodCalcs.uk
Sanding Schedule Calculator — Grit Progression
Plan grit progression and sandpaper quantities for wood preparation.
How We Calculate This
The calculator builds a grit progression from your start to finish grit using the woodworker's “golden rule”: each step is no more than about 50% higher than the last, so intermediate grades are skipped. A typical furniture run is 80 → 120 → 180 → 220 (4 steps), not every grade in between.
Sheets per grit ≈ Surface area ÷ 2 (one sheet covers ~2 m² before wearing out — an approximate rule of thumb; coarse grits on hardwood wear faster)
Frequently Asked Questions
Never skip more than one grit level. A typical progression for furniture is 80 → 120 → 180 → 220. For ultra-smooth finishes, continue to 320 or 400. Starting at 120 is fine for pre-planed timber.
As a rough guide, one sheet covers about 2 m² before wearing out. Coarser grits wear faster in hardwood. Always buy extra — running out mid-project is frustrating.
Only use 60 grit for removing paint, heavy scratches, or flattening rough-sawn timber. On pre-planed wood, start at 80 or 120 grit. Using too coarse a grit creates deep scratches that are hard to remove.
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Last updated: February 2026
All calculations are estimates. Always verify measurements and material quantities before cutting or purchasing.