Metres to Millimetres Converter
Convert metres to millimetres — multiply by 1,000, which is how most construction drawings are dimensioned. Results update as you type; exact factors shown.
One metre is 1,000 millimetres — see the exact factor, not a rounded rule of thumb.
How the metres to millimetres converter works
Every length is converted through the metre, the SI base unit of length. The inch has been defined as exactly 25.4 mm since the 1959 international yard and pound agreement, so a foot is exactly 0.3048 m, a yard 0.9144 m and a statute mile 1,609.344 m. The nautical mile is 1,852 m by international definition.
The UK is metric for most trade and science but keeps miles, pints, stone and mpg (with the imperial gallon) in daily life.
Common length conversions
| From | To | Units |
|---|---|---|
| 0.1 m | 100 mm | metres to millimetres |
| 0.25 m | 250 mm | metres to millimetres |
| 0.5 m | 500 mm | metres to millimetres |
| 1 m | 1,000 mm | metre to millimetres |
| 1.2 m | 1,200 mm | metres to millimetres |
| 1.8 m | 1,800 mm | metres to millimetres |
| 2.4 m | 2,400 mm | metres to millimetres |
| 3 m | 3,000 mm | metres to millimetres |
| 5 m | 5,000 mm | metres to millimetres |
| 10 m | 10,000 mm | metres to millimetres |
| 20 m | 20,000 mm | metres to millimetres |
| 100 m | 100,000 mm | metres to millimetres |
Units in this converter and their exact factors
| Unit | Symbol | One unit in metres |
|---|---|---|
| millimetre | mm | 0.001 metre |
| centimetre | cm | 0.01 metre |
| metre | m | 1 metre |
| kilometre | km | 1,000 metre |
| inch | in | 0.0254 metre |
| foot | ft | 0.3048 metre |
| yard | yd | 0.9144 metre |
| mile | mi | 1,609.344 metre |
| nautical mile | nmi | 1,852 metre |
FAQFrequently asked questions about length conversion
How many mm in a metre?
Exactly 1,000.
How do I convert m to mm?
Multiply by 1,000 — move the decimal three places right.
What is 2.4 m in mm?
2,400 mm, the standard plasterboard sheet length.
Why do trades quote in mm?
Whole millimetres remove decimal points from a drawing, which removes a whole class of reading errors.
What is 0.5 m in mm?
500 mm.
Where these figures come from
- BIPM — The International System of Units (SI Brochure, 9th edition) — definitions of the base and derived units.
- NIST Special Publication 811 — Guide for the Use of the International System of Units — the exact conversion factors used here.
- National Physical Laboratory (NPL) — United Kingdom's national measurement authority.
Last checked: September 2026. Conversion factors are fixed by definition and do not change with tax years or regulations.