Particle size · Sieve finder

Micron to Mesh Converter

Enter a particle or opening size in microns, millimeters or inches to find the closest mesh size and US standard sieve — and see whether it passes.

µm
20 µm5.6 mm

Closest sieve
100mesh
ASTM No. 100 · 150 µm opening
Your size
150 µm
Tyler equiv.
100 mesh
Finest it passes
No. 100
Theoretical
169 mesh

Comparing size with the nominal opening only, a 150 µm particle passes through a No. 100 sieve (150 µm).

HUMAN HAIR ≈ 70 µmPARTICLE 150 µm · PASSESOPENING 150 µmWIRE 100 µmPITCH 250 µm

Magnified schematic — the wire-to-opening ratio is true to scale; very thin lines are drawn at a minimum visible width.

SieveNo. 100
Opening150 µm
Particle150 µm
Zoom—

01 — ChartMicron to mesh chart

Microns (µm)US sieve / meshTyler meshmminches
20 µmNo. 6356350.020.0008
25 µmNo. 5005000.0250.001
32 µmNo. 4504500.0320.0013
38 µmNo. 4004000.0380.0015
45 µmNo. 3253250.0450.0018
53 µmNo. 2702700.0530.0021
63 µmNo. 2302500.0630.0025
75 µmNo. 2002000.0750.003
90 µmNo. 1701700.090.0035
106 µmNo. 1401500.1060.0042
125 µmNo. 1201150.1250.0049
150 µmNo. 1001000.150.0059
180 µmNo. 80800.180.0071
212 µmNo. 70650.2120.0083
250 µmNo. 60600.250.0098
300 µmNo. 50480.30.0118
355 µmNo. 45420.3550.014
425 µmNo. 40350.4250.0167
500 µmNo. 35320.50.0197
600 µmNo. 30280.60.0236
710 µmNo. 25240.710.028
850 µmNo. 20200.850.0335
1,000 µmNo. 181610.0394
1,180 µmNo. 16141.180.0465
1,400 µmNo. 14121.40.0551
1,700 µmNo. 12101.70.0669
2,000 µmNo. 10920.0787
2,360 µmNo. 882.360.0929
2,800 µmNo. 772.80.1102
3,350 µmNo. 663.350.1319
4,000 µmNo. 5540.1575
4,750 µmNo. 444.750.187
5,600 µmNo. 3½3.55.60.2205

02 — How it worksWhy micron to mesh is not a simple formula

A mesh number only tells you how many wires there are per inch. The opening depends on how thick those wires are. Dividing 25,400 by your micron size gives the number of openings per inch if the wire had zero thickness — real screens always need a lower mesh count to reach the same opening. That is why this tool matches your size to the nearest standard sieve instead.

If you are specifying custom wire cloth, use the wire mesh calculator to test combinations of mesh count and wire diameter.

03 — FAQFrequently asked questions

How do you convert microns to mesh?

For a rough estimate, divide 25,400 by the micron size (this ignores wire thickness, so it overstates the mesh). For a real screen, find the standard sieve whose opening is closest to your size — e.g. 150 µm is a No. 100 (100 mesh) sieve.

What mesh is 50 microns?

50 microns is between the No. 270 (53 µm) and No. 325 (45 µm) sieves. The closest standard size is 270 mesh.

What mesh is 100 microns?

100 microns is closest to the No. 140 sieve (106 µm), which is 150 mesh on the Tyler scale. The next finer sieve is No. 170 (90 µm).

What mesh is 25 microns?

25 microns is a No. 500 sieve (500 mesh) in ASTM E11.