Sandpaper grit chart
Grit numbers are not universal: US abrasives follow CAMI grades while nearly everything made in Europe follows FEPA's P-series, and past the fine end the same number means different scratch sizes. This chart lines both up against actual particle diameter.
| FEPA (EU) | Closest CAMI (US) | Nominal grain (µm) | Typical use |
|---|---|---|---|
| P12 | 16 | 1,815 | Very coarse — aggressive stock removal |
| P16 | 20 | 1,324 | |
| P20 | 24 | 1,000 | |
| P24 | 30 | 764 | Coarse — leveling, paint stripping |
| P30 | 36 | 642 | |
| P36 | 40 | 538 | |
| P40 | 50 | 425 | Coarse — shaping, first pass on raw wood |
| P50 | 60 | 336 | |
| P60 | 80 | 269 | Medium — fairing curves, sanding frames |
| P80 | 100 | 201 | |
| P100 | 120 | 162 | Medium — general purpose smoothing |
| P120 | 150 | 125 | |
| P150 | 180 | 100 | Fine — pre-sanding before final grits |
| P180 | 220 | 82 | |
| P220 | 240 | 66 | Fine — final wood prep before finish |
| P240 | 280 | 58.5 | |
| P280 | 320 | 52.2 | Very fine — sealer coats, between-coat work |
| P320 | 360 | 46.2 | |
| P360 | 400 | 40.5 | |
| P400 | 500 | 35 | Very fine — scuffing varnish and lacquer |
| P500 | 600 | 30.2 | |
| P600 | 800 | 25.8 | Ultra fine — wet sanding topcoats |
| P800 | 1000 | 21.8 | |
| P1000 | 1200 | 18.3 | Ultra fine — polishing, automotive prep |
| P1200 | 1500 | 15.3 | |
| P1500 | 2000 | 12.6 | Micro finishing — gloss leveling |
| P2000 | 2500 | 10.3 | |
| P2500 | 3000 | 8.4 | Mirror polishing with compound |
How to read a package correctly
Look for the standard, not just the number: "P220" is a FEPA grade, bare "220" on US retail paper usually means CAMI. The micron column is the honest comparison — it is the nominal grain diameter each grade allows, and it converts directly with our millimeter converters if you think in thousandths of an inch (1 µm ≈ 0.00004").
Frequently asked questions
Is FEPA P220 the same as CAMI 220?
No — this is the most common mix-up in mixed-toolbox shops. Below about P220 the two scales sit near each other, but above that they diverge fast: CAMI 320 at 36 µm cuts noticeably finer than P320 at 46 µm. When a plan written in one system calls out a grit, match the micron column, not the number.
Why can't the two scales be converted exactly?
They grade different things. FEPA P-grades are defined by sieves and sedimentation limits on the abrasive grain itself; CAMI grades describe coated products sold in the US market. A 'grade' is a band of particle sizes, not one particle, so any letter-to-number cross-reference is approximate by nature.
What sequence should I sand hardwood before oil or varnish?
A three-step jump works well: 120 to remove machine marks, 180 to erase 120's scratches, 220 last. Skipping more than one step leaves coarser scratches under the finish that show up after the first coat raises the grain.
FEPA grain sizes per FEPA 42-2 (coated abrasives) as cross-referenced by the Coated Abrasives Fabricators Association and Metallography.org; CAMI pairings are approximations because the standards define different distributions.