Mesh Size Calculator
Enter the mesh count, the number of openings per inch, and the wire diameter. The calculator gives the size of each opening in microns, millimetres and inches, and how much of the screen is open.
- Mesh to microns
- Open area
- Wire pitch
Measure the wire with a micrometer, or take it from the supplier's data sheet.
Mesh count is the number of openings in one inch. The opening is the pitch, 25.4 mm divided by the mesh, less the wire thickness. A 100 mesh screen with 0.1 mm wire has openings of about 154 microns.
Mesh to micron chart
Typical wire sizes. Search for a mesh.
| Mesh | Opening (µm) | Opening (mm) | Opening (in) |
|---|---|---|---|
| 10 | 2000 | 2 | 0.0787 |
| 20 | 850 | 0.85 | 0.0335 |
| 40 | 425 | 0.425 | 0.0167 |
| 60 | 250 | 0.25 | 0.0098 |
| 100 | 150 | 0.15 | 0.0059 |
| 200 | 75 | 0.075 | 0.0029 |
| 325 | 45 | 0.045 | 0.0017 |
| 400 | 38 | 0.038 | 0.0015 |
Close to ASTM E11 test sieves. Exact openings depend on the wire used.
Mesh count and opening
Wire about a third of the pitch. Slide the mesh count.
The close-up shows four openings of the weave. Coloured bars are the wires.
How to convert mesh to microns
Pitch less wire. Step through it.
Mesh count
Openings per inch.
For woven mesh, open area tells you how fast liquid or powder passes through. Higher is faster.
Woven wire, perforated plate or nylon
Screen types. Compare them.
Stainless or brass.
Punched holes.
Woven plastic.
Nylon and polyester meshes are used for fine filtering of liquids, inks and food.
Before ordering
Screen checks. Tick each item.
Tick each item as you go.
Check whether a supplier quotes mesh per inch or per centimetre, as some European sizes count per cm.
What you get
Mesh opening. Each tile explains one result.
µm and mm.
For US specs.
Per cent.
Wire to wire.
Stopped above.
The opening, not the mesh count, decides which particles pass.
Frequently Asked Questions
No question matches that search.
How do I convert mesh to microns?
Divide 25,400 by the mesh count, then subtract the wire diameter in microns.
What does mesh count mean?
The number of openings in one inch of screen.
What size particles pass a fine mesh?
Particles smaller than the opening. A 200 mesh sieve passes about 75 microns.
Does a higher mesh mean a finer screen?
Yes. More openings per inch means smaller openings.
Why does wire diameter matter?
Thicker wire takes up more of each pitch, so the opening is smaller and the open area lower.
What is open area?
The share of the screen that is open holes. More open area lets material through faster.
Are mesh sizes the same in every standard?
Close, but ASTM and ISO sieves differ slightly. Use the opening in microns to compare.
Know the real opening
Mesh count and wire size together give the opening that matters. Use it to choose sieves, filters and screens with confidence.
More size calculators
Each one has its own calculator, worked examples and answers to common questions.