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Sandpaper Grit Conversion Chart: CAMI to FEPA

CAMI, FEPA and JIS grits against actual particle size — including where they disagree.

Particle size

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microns · the real measure

CAMI / ANSI

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FEPA

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JIS

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Why Sandpaper Grit Charts Disagree

Any CAMI vs FEPA grit comparison runs into the same problem: there are three standards in common use, and they are not interchangeable. CAMI (ANSI B74.18) is the North American system, printed as a plain number. FEPA is the European one, printed with a P prefix. JIS is the Japanese standard, common on waterstones and wet-and-dry paper.

Below about 220 grit the three agree closely enough that you can treat the numbers as equivalent. Above 220 they diverge, and they keep diverging. By the fine end the gap is large: CAMI 600 is roughly P1200, not P600. Buy P600 expecting "600 grit" and you get paper about twice as coarse as you wanted.

The only reliable common ground is particle size in microns, which is why this chart leads with it.

Where the Charts Are Simply Guessing

Here is the part most pages will not tell you: ANSI B74.18 does not define grits finer than 600. There is no CAMI 800, no CAMI 1500, no CAMI 3000 in the standard.

So when a chart confidently lists CAMI equivalents up to 3000 grit, those numbers are manufacturer extrapolations presented as if they were standardised. They are not wrong so much as unfounded — different suppliers extrapolate differently, which is exactly why you will find charts that disagree with each other at the fine end.

This chart marks that boundary rather than papering over it. Above CAMI 600, compare microns and treat the grit number as a label, not a specification.

Grit Conversion Chart

Sandpaper grit conversion: FEPA, CAMI/ANSI, JIS and microns
Microns FEPA CAMI JIS Typical use
1815 µm P12 12 12 Stripping, heavy shaping
1324 µm P16 16 16 Stripping, heavy shaping
1000 µm P20 20 20 Stripping, heavy shaping
764 µm P24 24 24 Stripping, heavy shaping
642 µm P30 30 30 Stripping, heavy shaping
538 µm P36 36 36 Stripping, heavy shaping
425 µm P40 40 40 Stripping, heavy shaping
336 µm P50 50 50 Stripping, heavy shaping
269 µm P60 60 60 Stripping, heavy shaping
201 µm P80 80 80 Levelling, coarse sanding
162 µm P100 100 100 Levelling, coarse sanding
125 µm P120 120 120 Levelling, coarse sanding
100 µm P150 150 150 General smoothing
82 µm P180 180 180 General smoothing
68 µm P220 220 220 Before paint or stain
58.5 µm P240 220 240 Before paint or stain
52.2 µm P280 240 280 Before paint or stain
46.2 µm P320 280 280 Before paint or stain
40.5 µm P360 320 320 Between finish coats
35 µm P400 320 360 Between finish coats
30.2 µm P500 360 400 Between finish coats
25.8 µm P600 400 500 Between finish coats
21.8 µm P800 400 600 Between finish coats
18.3 µm P1000 500 700 Polishing, wet sanding
15.3 µm P1200 600 800 Polishing, wet sanding
12.6 µm P1500 800* 1000 Polishing, wet sanding
10.3 µm P2000 1000* 1200 Polishing, wet sanding
8.4 µm P2500 1200* 1500 Polishing, wet sanding

P grade sandpaper conversion here uses FEPA-P average particle size as the reference. CAMI and JIS columns are nearest equivalents, not exact matches. * marks CAMI figures above 600, which are extrapolations — ANSI B74.18 does not define them. Source: metallography.org, verified 5 August 2026.

Which Grit to Use

  • 40–60 — stripping paint, levelling badly uneven timber. Leaves deep scratches.
  • 80–100 — shaping and removing the scratches the coarse paper left.
  • 120–150 — general smoothing. Most projects start here.
  • 180–220 — final sanding before finish. This is where bare wood should end.
  • 320–400 — between coats of varnish or lacquer, sanded lightly.
  • 600+ — wet sanding, polishing, and metal finishing. A sandpaper grit chart for metal work lives almost entirely in this range and above.

Never skip more than one step. Each grit's job is to remove the scratches left by the previous one; jumping from 80 to 220 leaves 80-grit scratches that the finish will highlight rather than hide.

The Mistake That Costs a Finish

Sanding bare wood beyond about 220 before staining burnishes the surface — it polishes the fibres closed so they cannot absorb stain evenly. The result is blotchy, and it is not fixable without sanding back and starting again.

For paint, 150 to 180 is enough. For stain, stop at 180 to 220. Save the fine grits for sanding between finish coats, which is a different job with a different purpose.

Frequently Asked Questions

Is CAMI 600 grit the same as P600?

No, and this is the single most common mistake. CAMI 600 is roughly P1200 — about 15 microns. P600 is about 26 microns, which is closer to CAMI 400. Buying P600 when a plan calls for 600 grit gives you paper roughly twice as coarse as intended.

What is the difference between CAMI and FEPA grit?

They are two different standards with different particle-size distributions. CAMI is the North American system (ANSI B74.18), written as a bare number. FEPA is the European system, written with a P prefix. Below about 220 the numbers happen to align closely; above that they diverge sharply and keep diverging.

How do I tell which standard my sandpaper uses?

Look for the P. FEPA grits are printed as P80, P240, P1200. CAMI grits are printed as a plain number — 80, 240, 600. If there is no P and the paper is European, check the packaging, because some manufacturers print both. When only one number is given and you cannot tell, the micron figure is the reliable comparison.

What grit is fine sandpaper?

Roughly 150 to 180 is fine, 220 to 240 is very fine, and above 320 is extra fine. Those bands are conventions rather than a standard, so they shift between manufacturers. The particle size in microns is the objective measure: fine paper is around 80 to 100 microns, extra fine below 45.

Why do sandpaper grit charts disagree with each other?

Because above CAMI 600 there is nothing left to agree on. ANSI B74.18 does not define grits finer than 600, so every finer equivalence you see is a manufacturer's own extrapolation. Charts that publish confident numbers up to 3000 grit are presenting estimates as if they were standards.

What grit should I use before painting or staining?

For bare wood, finish at 150 to 180 before painting and 180 to 220 before staining. Going finer than 220 on wood you intend to stain can burnish the surface and stop it absorbing evenly, which produces a blotchy finish. More sanding is not always better.

What is JIS grit?

The Japanese Industrial Standard, JIS R6010. It sits between CAMI and FEPA in the fine range and is common on Japanese waterstones and wet-and-dry papers. JIS 1000 is about 18 microns, which is roughly P1000 and roughly CAMI 500 — the three systems using the same number for genuinely different things.

What grit sandpaper is equivalent to 0000 steel wool?

Very approximately 400 to 600 CAMI, but the comparison is loose because steel wool cuts by a completely different mechanism. Steel wool conforms to a surface and burnishes; abrasive paper cuts. For a comparable finish on a flat surface, start around 400 CAMI and test on an offcut.

Does higher grit always mean smoother?

Within one standard, yes — a higher number means smaller particles and a finer scratch pattern. Across standards, no, which is the whole problem. P800 has larger particles than CAMI 600 despite the larger number. Compare microns, not grit numbers, whenever the standards differ.

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