Mesh-to-Micron Conversion Chart
Wire mesh is sold by mesh count — but filtration is often specified in microns. This chart converts between them, with the exact opening size and open area for standard mill weaves. Family-owned and stocked in Hayward, CA since 1938.
Quick reference — the sizes people ask for most
Full Conversion Table
Mesh count is the number of openings per linear inch. As the mesh number goes up, the openings get smaller. The opening below is the clear space between wires (aperture) for a standard weave; percentages are the open area.
| Mesh Count |
Opening (inches) |
Opening (mm) |
Opening (microns) |
Open Area |
Typical Use |
|---|---|---|---|---|---|
| 2 | 0.4370" | 11.100 | 11,100 | 76% | Coarse screening & guards |
| 3 | 0.2863" | 7.273 | 7,273 | 74% | Coarse screening & guards |
| 4 | 0.2030" | 5.156 | 5,156 | 66% | Coarse screening & guards |
| 5 | 0.1590" | 4.039 | 4,039 | 63% | Coarse screening & guards |
| 6 | 0.1317" | 3.344 | 3,344 | 62% | Coarse screening & guards |
| 8 | 0.0970" | 2.464 | 2,464 | 60% | Coarse screening & guards |
| 10 | 0.0750" | 1.905 | 1,905 | 56% | Coarse screening & guards |
| 12 | 0.0603" | 1.532 | 1,532 | 52% | Coarse screening & guards |
| 14 | 0.0514" | 1.306 | 1,306 | 52% | Coarse screening & guards |
| 16 | 0.0445" | 1.130 | 1,130 | 51% | Coarse screening & guards |
| 18 | 0.0386" | 0.979 | 979 | 48% | Sifting & separation |
| 20 | 0.0340" | 0.864 | 864 | 46% | Sifting & separation |
| 24 | 0.0277" | 0.703 | 703 | 44% | Sifting & separation |
| 30 | 0.0213" | 0.542 | 542 | 41% | Sifting & separation |
| 40 | 0.0150" | 0.381 | 381 | 36% | Sifting & separation |
| 50 | 0.0110" | 0.279 | 279 | 30% | Sifting & separation |
| 60 | 0.0092" | 0.233 | 233 | 30% | General filtration |
| 80 | 0.0070" | 0.178 | 178 | 31% | General filtration |
| 100 | 0.0055" | 0.140 | 140 | 30% | General filtration |
| 120 | 0.0046" | 0.118 | 118 | 31% | General filtration |
| 150 | 0.0041" | 0.103 | 103 | 37% | General filtration |
| 200 | 0.0029" | 0.074 | 74 | 34% | Fine / micron filtration |
| 250 | 0.0024" | 0.061 | 61 | 36% | Fine / micron filtration |
| 325 | 0.0017" | 0.043 | 43 | 30% | Fine / micron filtration |
| 400 | 0.0015" | 0.038 | 38 | 36% | Fine / micron filtration |
1 inch = 25,400 microns · Opening = (1 ÷ mesh) − wire diameter · Values use standard mill wire diameters; exact specs vary by weave. See each product's spec sheet for its precise opening.
Not sure which mesh you need?
Tell us the micron rating or opening — we'll match it and cut to size.
How Mesh & Micron Relate
What is "mesh count"?
Mesh count is how many openings there are per linear inch, counted from the center of one wire to a point one inch away. A 4 mesh screen has 4 openings per inch (coarse); a 200 mesh cloth has 200 (very fine). Because thicker wire takes up more space, two cloths with the same mesh count can have different openings — so the wire diameter matters too.
What is a "micron"?
A micron (µm) is one-millionth of a meter — 25,400 of them per inch. Filtration and particle specs use microns because they describe the actual particle size that passes through, independent of wire thickness. That's why an engineer will say "I need 150 micron" rather than a mesh number.
Reading the chart
Find your target micron in the table and read across to the mesh count — that's the cloth to order. If your spec falls between two rows, choose the finer (higher) mesh to be safe. For anything below ~40 microns, ask us about our fine stainless filtration cloth and Dutch weaves.
Common Questions
How many microns is 100 mesh?
A standard 100 mesh woven cloth (.0045" wire) has an opening of about 140 microns (0.0055" / 0.14 mm). It's a common choice for general liquid and paint filtration.
What micron is 200 mesh?
Roughly 74 microns (.0021" wire, 0.074 mm opening) — a fine filtration cloth used for inks, coatings, and fluids.
Which is finer — a higher or lower mesh number?
Higher mesh = finer. More openings per inch means each opening is smaller. 325 mesh (~43 microns) is far finer than 20 mesh (~864 microns).
Does wire diameter change the micron rating?
Yes. For the same mesh count, thicker wire leaves a smaller opening. Our chart uses standard mill wire diameters; for an exact opening, check the product's spec sheet or ask us — we can weave custom wire diameters.
Do you carry all of these mesh sizes?
Yes — Howard Wire stocks woven mesh from 1 mesh through 500 mesh in 304/316 stainless, aluminum, brass, copper and more, cut to size. Browse the full range or request a quote.