Millimetres to Micrometres Converter

Convert millimetres (mm) to micrometres (µm) instantly. Enter a value in millimetres and this converter returns the equivalent in micrometres, using the exact factor of 1,000. One millimetre is 1,000 micrometres, and one micrometre is 0.001 millimetres, so you can convert either way. The factor follows the standard definitions of the metre and the international inch, so it is consistent and reliable for school work, trade, engineering, travel and everyday measuring. The formula, a worked example and a quick-reference table are below.

Value in millimetres (mm)

1 mm =1,000 µm

1 µm =0.001 mm

The formula

Multiply millimetres by 1,000 to get micrometres. In symbols, µm = mm × 1,000. To go the other way, multiply micrometres by 0.001 to get millimetres.

Worked example

Convert 10 millimetres to micrometres: 10 × 1,000 = 10,000 micrometres.

Quick reference

Millimetres	Micrometres
1 mm	1,000 µm
2 mm	2,000 µm
5 mm	5,000 µm
10 mm	10,000 µm
25 mm	25,000 µm
50 mm	50,000 µm
100 mm	100,000 µm

Frequently asked questions

How many micrometres are in one millimetre?

One millimetre equals 1,000 micrometres. Multiply the number of millimetres by 1,000 to convert.

What is the formula to convert millimetres to micrometres?

Millimetres times 1,000 equals micrometres. To reverse it, multiply micrometres by 0.001 to get millimetres.

Is the mm to µm conversion exact?

The factor comes from the standard definitions of the metre and the international inch (0.0254 m exactly), so the underlying conversion is exact. Displayed results are rounded for readability.

Who this converter is for

This converter is for students, tradespeople, travellers and anyone who needs to change millimetres into micrometres quickly and accurately.

What this converter assumes

You enter a length in millimetres.
The factor used is 1,000 micrometres per millimetre.
Results are rounded for display.

Sources

Related converters

Length Converter: convert between any length units.
Unit Converter: convert many kinds of units.
Millimetres to Centimetres Converter: convert millimetres to centimetres.
Millimetres to Metres Converter: convert millimetres to metres.

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