Screen sizes are quoted three ways — U.S. mesh count, microns, and inches — and every filtration conversation eventually needs to convert between them. This chart covers the full practical range. Quick rule of thumb: mesh × microns ≈ 15,000 (so 100 mesh ≈ 150 µm).

Mesh to Micron Conversion Chart

U.S. Mesh	Microns (µm)	Inches	Millimeters
4	4760	0.187	4.76
6	3360	0.132	3.36
8	2380	0.0937	2.38
10	2000	0.0787	2.00
12	1680	0.0661	1.68
14	1410	0.0555	1.41
16	1190	0.0469	1.19
18	1000	0.0394	1.00
20	841	0.0331	0.841
25	707	0.0278	0.707
30	595	0.0234	0.595
35	500	0.0197	0.500
40	400	0.0165	0.400
45	354	0.0139	0.354
50	297	0.0117	0.297
60	250	0.0098	0.250
70	210	0.0083	0.210
80	177	0.0070	0.177
100	149	0.0059	0.149
120	125	0.0049	0.125
140	105	0.0041	0.105
170	88	0.0035	0.088
200	74	0.0029	0.074
230	63	0.0025	0.063
270	53	0.0021	0.053
325	44	0.0017	0.044
400	37	0.0015	0.037
450	32	0.0013	0.032
500	25	0.0010	0.025
635	20	0.0008	0.020

Reference Points

For a feel of scale: human hair is roughly 70 µm, the naked eye resolves about 40 µm, table salt is ~100 µm, and a white blood cell is ~25 µm. Bag filtration typically operates between 1 and 800 µm — felt bags cover 1–200 µm, mesh bags 35–800 µm.

Know the micron you need? Request a quote or call 800-554-8555.