# mm to m Converter URL: https://speedycalculator.com/calculators/conversion/mm-to-m/ Last updated: 2026-10-25 > Convert millimetres (mm) to metres (m): 1 millimetre = 0.001 m, so multiply by 0.001 or divide by 1,000. Both fields are editable, so you can also type in metres and get millimetres back. ## Inputs - Millimetres (mm) ## Results - Metres ## Formula ``` 1 mm = 0.001 m 1 m = 1,000 mm m = mm × 0.001 ``` ## Explanation Divide millimetres by 1,000 to get metres. Construction drawings in metric countries are dimensioned in millimetres, so 2,400 mm is a 2.4 m wall. ### How to use the mm to m Converter - Type the number of millimetres into the **Millimetres** field. Decimals such as 500 are fine. - Read the answer in **Metres** – it updates as you type, with no button to press. - To convert the other way, type into **Metres** and the millimetres are recalculated. - Press **Copy results** to copy both values with the page title, or **Copy link** to share this exact conversion. This page converts only mm ⇄ m. Need a different unit? Use the general length converter, where you can choose any “from” and “to” unit. ### How it works Both units measure length, so they are always in the same ratio: one millimetre equals 0.001 metres. The calculator multiplies the number of millimetres you type by 0.001 to give metres, and when you type into the metres field it divides by the same factor to give millimetres. Because the ratio never changes, doubling the millimetres always doubles the metres. Results are calculated at full precision and rounded only for display (up to eight decimal places, with very large or small values shown in scientific notation). ### How to convert millimetres to metres - Write down the value in millimetres, for example **1,000 mm**. - Multiply by the conversion factor 0.001 (because 1 millimetre = 0.001 m). - 1,000 × 0.001 = **1 m**. - To go back from metres to millimetres, divide by 0.001 – or multiply by 1,000. ### mm to m conversion table MillimetresMetresMetresMillimetres1 mm0.001 m1 m1,000 mm10 mm0.01 m2 m2,000 mm100 mm0.1 m5 m5,000 mm250 mm0.25 m10 m10,000 mm500 mm0.5 m20 m20,000 mm1,000 mm1 m50 m50,000 mm1,200 mm1.2 m100 m100,000 mm2,400 mm2.4 m1,000 m1,000,000 mm3,000 mm3 m6,000 mm6 m ### What is a millimetre? A millimetre is one thousandth of a metre. Engineering drawings, construction plans, rainfall, screws, bolts and jewellery are all dimensioned in millimetres. ### What is a metre? The metre is the SI base unit of length. Since 1983 it has been defined as the distance light travels in a vacuum in 1/299,792,458 of a second, which ties it to a fundamental constant rather than a physical bar of metal. ### Common mistakes to avoid Mixing the international foot (0.3048 m) with the old u.s. survey foot, confusing nautical and statute miles, and writing decimal feet such as 5.5 ft as “5 ft 5 in” (it is 5 ft 6 in). ## Worked example Inputs — Millimetres: 1,000 mm. Results — **Metres = 1 m**. ## FAQ **How many metres is 2,400 mm?** 2.4 m. **How many mm in a metre?** 1,000. **How do I convert millimetres to metres?** Multiply the number of millimetres by 0.001. For example, 1,000 mm × 0.001 = 1 m. **How do I convert metres back to millimetres?** Divide by 0.001 (or multiply by 1,000), or simply type the value into the metres field above. **What is 10 mm in metres?** 10 mm = 0.01 m. **What is 100 mm in metres?** 100 mm = 0.1 m. **Is this conversion exact?** Yes. The factor comes from the official definitions of both units (NIST and the SI), so the only difference you may see is rounding in the last displayed digit. **Can I convert to other units on this page?** This page converts only between millimetres and metres. To pick any length unit, use the general length converter linked under Related calculators. **What formula does the mm to m Converter use?** 1 mm = 0.001 m. ## Sources - [NIST Special Publication 811 – Guide for the Use of the International System of Units](https://www.nist.gov/pml/special-publication-811) - [NIST Handbook 44 Appendix C – General tables of units of measurement](https://www.nist.gov/pml/owm/nist-handbook-44-current-edition)