Mesh to Micron Converter

Convert a US mesh size into its opening size in microns.

Covers 30 standard sieve sizes from 3 to 400 mesh.

Updated August 1, 2026

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Mesh and micron are two ways of describing how fine a screen is — one counts openings per inch, the other measures the opening in micrometres. This guide explains how the converter works, walks through real examples from labs and workshops, and lays out the ideas behind the numbers so you can trust every result.

→Introduction / overview
→How to use / quick start
→Real-world examples
→Common scenarios & when to use
→Tips & best practices
→Calculation method / formulas
→Related concepts
→FAQs, limitations, sources

Introduction / overview

The Mesh to Micron Converter takes a mesh number — the count of openings in one linear inch of screen — and returns the width of those openings in microns. Pick any of the 30 standard US sieve sizes in the dropdown, from a coarse 3 mesh up to a very fine 400 mesh, and the matching opening size appears instantly.

If you have ever seen “200 mesh” printed on a bag of powder and wondered what that really means in microns, or read “74 μm” on a datasheet and needed to know which sieve that corresponds to, this tool is the quick bridge between the two. It’s the kind of lookup you’d otherwise be flipping through a printed conversion chart for — now it happens the moment you click.

The values follow the widely used US standard sieve series — the same empirical mesh-to-micron chart used across labs and industry. It’s a dependable everyday reference, not a guess.

Who is this for?

Lab technicians and QC staff reading sieve-analysis results or checking screen specifications.
Abrasive, filtration, and screening suppliers translating product mesh numbers into opening sizes for customers.
Food and beverage processors matching sieves and filter screens to the fineness they need.
Students and hobbyists who hit “mesh” in a recipe, kit, or datasheet and just want the answer.

The opening width is really just a length, so when you need it in millimetres or inches — for a drawing, a parts list, or a quick sanity check — our Length Converter is a handy companion that turns that micron value into whatever unit you prefer.

How to use / quick start

1Open the Mesh dropdown and pick the sieve size you are working with — for example, 100.
2Read the Microns field — it fills in immediately with the opening size. It is read-only and calculated from the mesh you selected, so there is nothing else to type.
3Compare sizes by flipping through the options. Change the mesh any time and the micron value updates to match, which makes it easy to spot how a 100-mesh screen compares with a 400-mesh one.

Quick example: a 100-mesh screen

Select 100 from the Mesh dropdown.

The Microns field immediately shows 149 — the opening size for 100 mesh.

100\ \text{mesh}

\to

149\ \mu\text{m}

Pick 400 instead and the same screen family drops to $37\ \mu\text{m}$ — a much finer opening. The larger the mesh number, the smaller the holes.

How to interpret the result

The micron value is the width of each opening, not the wire thickness or the total screen pitch.
A smaller micron number means a finer screen. 37 μm openings catch much smaller particles than 149 μm openings.
Use it as a reference lookup: the value tells you what size particle the screen lets through and what it holds back.

Real-world examples / use cases

1) Laboratory sieve analysis of soil

Background: A geotechnical lab runs a soil sample through a nest of sieves to plot its grain-size curve. The 200-mesh sieve is the classic marker where sand is retained and finer silt or clay passes through.

Input: Select 200 in the Mesh dropdown.

200\ \text{mesh}

\to

74\ \mu\text{m}

What it means: The 200-mesh sieve separates particles at roughly 74 μm. Knowing that threshold helps you read the grain-size distribution and classify the soil consistently.

2) Abrasive blasting media

Background: Sandblasting media is graded by mesh, and 60 mesh is a common medium grit for stripping paint and rust without gouging the surface underneath.

Input: Select 60 in the Mesh dropdown.

60\ \text{mesh}

\to

250\ \mu\text{m}

What it means: Each grit particle is about 250 μm across. Pairing the mesh number with the micron size helps you judge whether the media will give an aggressive or a gentler finish.

3) Fine filtration in food & drink

Background: A small-batch brewer wants a very fine screen to hold back sediment and fine particles in the finished product.

Input: Select 400 in the Mesh dropdown.

400\ \text{mesh}

\to

37\ \mu\text{m}

What it means: The screen blocks particles down to about 37 μm — well below what the eye can see. That level of fineness tells you the screen is built for polishing, not just straining.

4) Water intake strainer

Background: You’re choosing a strainer for a pump intake and want to keep out fine sand and silt while keeping water flowing.

Input: Select 100 in the Mesh dropdown.

100\ \text{mesh}

\to

149\ \mu\text{m}

What it means: The strainer catches particles larger than about 149 μm — roughly the size of fine sand. It’s a balanced choice when you want protection without too much flow restriction.

Common scenarios / when to use

Lab & quality control

Translate sieve numbers into opening sizes when writing up sieve-analysis results, checking test-sieve specs, or comparing methods across labs that report in microns.

Abrasives & blasting

Media is graded by mesh. Quickly find the micron size of a grit to match the surface finish you are aiming for, and compare supplier specifications that quote different units.

Filtration & strainers

Screen and mesh specifications in water treatment, HVAC, and process filtration are often quoted in mesh — convert to microns to judge what particle size actually gets trapped.

Powders & coatings

Pigments, coatings, and powdered materials list particle fineness in mesh. Convert to microns to compare products and interpret particle-size specifications consistently.

This calculator works well when:

You have a standard mesh number (3 to 400) and need its opening size in microns.
You want to compare several sieve sizes side by side without a printed chart.
You are double-checking a datasheet or supplier spec that mixes mesh and micron figures.

It may not be what you need when:

Your screen is described in fractional inches (for example “1/16 in”) rather than a mesh number — the Inches to Fraction Calculator is the better tool for that framing.
You need a mesh value that is not one of the 30 standard sizes — the dropdown follows the standard series, so pick the nearest available size.
You are after certified, calibrated sieve work for compliance — a reference converter can’t replace a verified test sieve.

Tips & best practices

Remember: bigger mesh, finer screen
The relationship is inverse — a 400-mesh screen has smaller openings ( $37\ \mu\text{m}$ ) than a 100-mesh screen ( $149\ \mu\text{m}$ ). Getting this backwards is the most common slip, so glance at the micron value whenever you pick a size.
Sanity-check with the 14,900 rule
Between 50 and 400 mesh, a quick approximation is $\mu\text{m} \approx \frac{14{,}900}{\text{mesh}}$ . For 100 mesh that gives about 149 μm — a handy way to spot a mistyped selection.
Know which standard you’re quoting
Mesh numbers are not fully interchangeable across systems. This calculator follows the US standard sieve series, so if a supplier quotes ISO or another national series, the micron value can differ slightly — worth confirming when precision matters.
Pick the nearest standard size
The dropdown offers the standard series from 3 to 400 mesh. If your product cites an unusual number, choose the closest standard size and note the micron difference rather than guessing an exact conversion.
Think of microns in everyday scale
A micron is one thousandth of a millimetre: $1\ \mu\text{m} = 0.001\ \text{mm}$ . So 74 μm is about 0.074 mm — thinner than a sheet of paper — which makes the “how fine is fine?” question much easier to picture.

Calculation method / formula explanation

Because the opening size of a woven screen depends on the thickness of the wire it is made from, mesh and microns don’t follow one single exact formula. The converter therefore uses the standard mesh-to-micron chart from the US standard sieve series — the empirical values most labs and suppliers work with. A couple of rules of thumb can still help you reason about the numbers.

Experimental rule of thumb (works well for 50–400 mesh)

\mu\text{m}

\approx

\frac{14{,}900}{\text{mesh}}

Divide 14,900 by the mesh number to estimate the opening in microns.

\text{Example: } \frac{14{,}900}{100}

\approx

149\ \mu\text{m}

The physical idea behind mesh

One inch is 25,400 microns. If you add the width of one opening ( $d_\text{open}$ ) and the width of one wire ( $d_\text{wire}$ ) in microns, the mesh number is how many of those units fit across one inch:

\text{mesh} = \frac{25{,}400}{d_\text{open} + d_\text{wire}}

This shows why there isn’t a universal mesh-to-micron formula: for the same mesh number, a screen made with thicker wire has smaller openings. The standard chart pins down one consistent set of values so everyone can compare apples to apples.

A few values straight from the chart

100\ \text{mesh}

\to

149\ \mu\text{m}

200\ \text{mesh}

\to

74\ \mu\text{m}

400\ \text{mesh}

\to

37\ \mu\text{m}

60\ \text{mesh}

\to

250\ \mu\text{m}

Where do the numbers come from?

The chart follows the standard US sieve series (ASTM E11 is the corresponding US standard for woven-wire test sieves). These are established reference values used across granulometry and particle-size work, not numbers derived from a single formula — which is exactly why a chart-based lookup is the honest way to present them.

Related concepts / background info

What is mesh?

In screening, mesh counts the number of openings in one linear inch of screen cloth. A “100-mesh” screen has roughly 100 openings per inch. Because the wire takes up space too, the mesh number is a count, not a direct measurement of the opening — which is why you need a chart to get from mesh to microns.

What is a micron?

A micron (symbol $\mu\text{m}$ ) is a micrometre — one millionth of a metre. That’s a thousandth of a millimetre: $1\ \mu\text{m} = 0.001\ \text{mm}$ . To give you a feel for the scale, a human hair is roughly 20 to 200 μm thick, so a 74 μm opening is in the same ballpark as the fine end of a hair.

Why the two move in opposite directions

More openings squeezed into an inch means each opening must be smaller. So as the mesh number goes up, the micron value goes down. That inverse relationship is the single most useful thing to remember about mesh-to-micron conversions — it keeps you from accidentally grabbing a much coarser or much finer screen than you intended.

Standards and why they matter

Several standard sieve series exist around the world — the US standard (ASTM E11), international (ISO 3310-1), and European (EN 933-1) series among them. They give very similar but not always identical values for the same mesh number. When a micron figure needs to match a specific spec sheet, it’s worth knowing which series that spec follows. This calculator uses the standard US sieve values.

Where this fits in granulometry

Sieve analysis is a core technique in granulometry — the study of particle sizes. A sample is shaken through a stack of sieves with progressively finer openings, and the amount caught on each one builds a particle-size distribution. Knowing each sieve’s opening in microns lets you read that distribution and describe a material the same way the rest of the industry does.

Frequently asked questions (FAQs)

What does a mesh number actually mean?

It’s the number of openings in one linear inch of the screen. A 100-mesh screen has about 100 openings per inch. The openings are smaller than the inch divided by 100 because the wire itself takes up part of that space.

How many microns is 100 mesh?

149 microns. Select $100$ in the Mesh dropdown and the converter returns $149\ \mu\text{m}$ . The 14,900 rule of thumb gives the same answer, since $14900 \div 100 = 149$ .

Is a bigger mesh finer or coarser?

Finer. A bigger mesh number means more openings per inch, so each opening is smaller. For example 400 mesh is $37\ \mu\text{m}$ while 200 mesh is $74\ \mu\text{m}$ — the 400-mesh screen has the smaller openings.

Why isn’t there one exact formula for mesh to micron?

Because the opening size depends on the thickness of the wire used to weave the screen. For the same mesh number, thicker wire leaves smaller openings. That’s why the conversion is based on a standard chart rather than a single equation.

How do I convert microns back to mesh?

For values in the 50–400 mesh range, the experimental rule is $\text{mesh} \approx \frac{14{,}900}{\mu\text{m}}$ — for example, about 149 μm maps back to roughly 100 mesh. Since this calculator works from the mesh dropdown, the practical step is to pick the standard mesh size nearest to your micron value.

What is a micron in millimetres?

A micron is one thousandth of a millimetre: $1\ \mu\text{m} = 0.001\ \text{mm} = 10^{-6}\ \text{m}$ . So the 74 μm opening of a 200-mesh screen is about 0.074 mm.

Can I type a custom mesh number instead of selecting one?

No — the mesh input is a dropdown of the 30 standard US sieve sizes from 3 to 400 mesh, and the Microns field is read-only. If your material cites an unusual value, choose the closest standard size and treat the result as a reference.

Limitations & disclaimer

The chart follows the US standard sieve series. ISO, European, and other national series can give slightly different opening sizes for the same mesh number.
Only the 30 standard mesh sizes (3 to 400) are available, and the Microns field is read-only, so custom mesh values can’t be entered.
This is an everyday reference tool for informational and educational use. For certified, calibrated sieve work — for example regulatory or compliance testing — always use verified test sieves and follow the applicable standard procedure.

External references / sources

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