Mesh number counts openings per linear inch, but the actual opening also depends on wire thickness, so there is no simple formula. Standard sieves follow the ASTM E11 table used here; a 200-mesh sieve passes particles up to 74 µm.
How to use the Mesh to Micron Converter
- Mesh (U.S. sieve number)
Results update as you type, and every field accepts the units shown in its menu.
How it works
Choose a mesh number and the calculator returns the nominal opening from the standard table.
U.S. sieve sizes
| Mesh | Opening (µm) | Opening (in) |
|---|---|---|
| 3 | 6730 | 0.2650 |
| 4 | 4760 | 0.1874 |
| 5 | 4000 | 0.1575 |
| 6 | 3360 | 0.1323 |
| 7 | 2830 | 0.1114 |
| 8 | 2380 | 0.0937 |
| 10 | 2000 | 0.0787 |
| 12 | 1680 | 0.0661 |
| 14 | 1410 | 0.0555 |
| 16 | 1190 | 0.0469 |
| 18 | 1000 | 0.0394 |
| 20 | 841 | 0.0331 |
| 25 | 707 | 0.0278 |
| 30 | 595 | 0.0234 |
| 35 | 500 | 0.0197 |
| 40 | 420 | 0.0165 |
| 45 | 354 | 0.0139 |
| 50 | 297 | 0.0117 |
| 60 | 250 | 0.0098 |
| 70 | 210 | 0.0083 |
| 80 | 177 | 0.0070 |
| 100 | 149 | 0.0059 |
| 120 | 125 | 0.0049 |
| 140 | 105 | 0.0041 |
| 170 | 88 | 0.0035 |
| 200 | 74 | 0.0029 |
| 230 | 63 | 0.0025 |
| 270 | 53 | 0.0021 |
| 325 | 44 | 0.0017 |
| 400 | 37 | 0.0015 |
What each result means
- Opening size = [Mesh (U.S. sieve number)] × 1e-6
- In millimetres = [Mesh (U.S. sieve number)] ÷ 1000
Formula
opening size = value from the ASTM E11 sieve tableWorked example
Inputs — Mesh (U.S. sieve number): No. 200.
Results — Opening size = 74 µm; In millimetres = 0.074 mm.
Frequently asked questions
What size is 200 mesh in microns?
74 µm.
What is the difference between mesh and micron?
Mesh counts openings per inch; micron is the opening size itself.
What formula does the Mesh to Micron Converter use?
opening size = value from the ASTM E11 sieve table.