Hayward, California

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.

Howard Wire Cloth Co. mascot
Howard Wire Cloth Co.

Mesh to Micron Conversion Chart

Quick reference — the sizes people ask for most

20MESH
864 microns0.0340" · 0.864 mm opening Shop 20 mesh →
40MESH
381 microns0.0150" · 0.381 mm opening Shop 40 mesh →
80MESH
178 microns0.0070" · 0.178 mm opening Shop 80 mesh →
100MESH
140 microns0.0055" · 0.140 mm opening Shop 100 mesh →
200MESH
74 microns0.0029" · 0.074 mm opening Shop 200 mesh →
325MESH
43 microns0.0017" · 0.043 mm opening Shop 325 mesh →

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 Shop
2 0.4370" 11.100 11,100 76% Coarse screening & guards Shop 2 mesh →
3 0.2863" 7.273 7,273 74% Coarse screening & guards Shop 3 mesh →
4 0.2030" 5.156 5,156 66% Coarse screening & guards Shop 4 mesh →
5 0.1590" 4.039 4,039 63% Coarse screening & guards Shop 5 mesh →
6 0.1317" 3.344 3,344 62% Coarse screening & guards Shop 6 mesh →
8 0.0970" 2.464 2,464 60% Coarse screening & guards Shop 8 mesh →
10 0.0750" 1.905 1,905 56% Coarse screening & guards Shop 10 mesh →
12 0.0603" 1.532 1,532 52% Coarse screening & guards Shop 12 mesh →
14 0.0514" 1.306 1,306 52% Coarse screening & guards Shop 14 mesh →
16 0.0445" 1.130 1,130 51% Coarse screening & guards Shop 16 mesh →
18 0.0386" 0.979 979 48% Sifting & separation Shop 18 mesh →
20 0.0340" 0.864 864 46% Sifting & separation Shop 20 mesh →
24 0.0277" 0.703 703 44% Sifting & separation Shop 24 mesh →
30 0.0213" 0.542 542 41% Sifting & separation Shop 30 mesh →
40 0.0150" 0.381 381 36% Sifting & separation Shop 40 mesh →
50 0.0110" 0.279 279 30% Sifting & separation Shop 50 mesh →
60 0.0092" 0.233 233 30% General filtration Shop 60 mesh →
80 0.0070" 0.178 178 31% General filtration Shop 80 mesh →
100 0.0055" 0.140 140 30% General filtration Shop 100 mesh →
120 0.0046" 0.118 118 31% General filtration Shop 120 mesh →
150 0.0041" 0.103 103 37% General filtration Shop 150 mesh →
200 0.0029" 0.074 74 34% Fine / micron filtration Shop 200 mesh →
250 0.0024" 0.061 61 36% Fine / micron filtration Shop 250 mesh →
325 0.0017" 0.043 43 30% Fine / micron filtration Shop 325 mesh →
400 0.0015" 0.038 38 36% Fine / micron filtration Shop 400 mesh →

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.