mm to inches – convert millimetres to inches
Convert millimetres to inches (mm to in) for DIY projects, screen sizes, CNC work, 3D printing and more. This page opens the main length converter with mm → inches pre-selected.
Open the interactive mm → inches converter:
Use main converter (mm → in) or switch to inches → mmOn the homepage you can quickly swap between mm, cm, inches, feet, yards and metres.
Quick reference: mm to inches
Since 1 in = 25.4 mm, you can convert mm to inches by dividing by 25.4. Some examples:
| Millimetres (mm) | Inches (in, approx.) |
|---|---|
| 10 mm | 0.39 in |
| 20 mm | 0.79 in |
| 25 mm | 0.98 in |
| 50 mm | 1.97 in |
| 100 mm | 3.94 in |
| 200 mm | 7.87 in |
| 1,000 mm | 39.37 in |
Why convert mm to inches?
Typical use cases for mm → inches include:
- Comparing metric product sizes with imperial-only catalogues.
- Reading US-based woodworking or engineering drawings.
- Checking bicycle, car or motorbike part sizes across regions.
- Translating 3D printer or CNC settings between unit systems.
More length converters on this site
All length conversions on the homepage go via metres, which keeps mm, cm, inches, feet and yards consistent.
Page last updated: 2 December 2025.