Convert Millimetre to Inch
1 millimetre = 0.03937008 inch (in). For example, 10 millimetre = 0.3937008 inch and 100 millimetre = 3.937008 inch. Type any value below to convert millimetre to inch both ways — it runs entirely in your browser.
Millimetre to Inch conversion formula
To convert millimetre to inch, multiply by 0.03937008:
inch = millimetre × 0.03937008
Going the other way, 1 inch = 25.4 millimetre, so
millimetre = inch × 25.4.
Millimetre to Inch — worked examples
| Millimetre | Inch |
|---|---|
| 1 mm | 0.03937008 in |
| 2 mm | 0.07874016 in |
| 3 mm | 0.1181102 in |
| 5 mm | 0.1968504 in |
| 10 mm | 0.3937008 in |
| 25 mm | 0.984252 in |
| 50 mm | 1.968504 in |
| 100 mm | 3.937008 in |
Millimetre ↔ Inch reference table
| Millimetre → Inch | Inch → Millimetre |
|---|---|
| 1 mm = 0.03937008 in | 1 in = 25.4 mm |
| 2 mm = 0.07874016 in | 2 in = 50.8 mm |
| 5 mm = 0.1968504 in | 5 in = 127 mm |
| 10 mm = 0.3937008 in | 10 in = 254 mm |
| 20 mm = 0.7874016 in | 20 in = 508 mm |
| 50 mm = 1.968504 in | 50 in = 1,270 mm |
| 100 mm = 3.937008 in | 100 in = 2,540 mm |
| 250 mm = 9.84252 in | 250 in = 6,350 mm |
| 500 mm = 19.68504 in | 500 in = 12,700 mm |
| 1000 mm = 39.37008 in | 1000 in = 25,400 mm |
About millimetre and inch
Millimetre: A millimetre is one-thousandth of a metre.
Inch: An inch is exactly 2.54 cm (1/12 of a foot).
The metric units (km, m, cm, mm, µm) are exact by definition, and the imperial units (mile, yard, foot, inch, nautical mile) use their exact international values. Traditional units (hand, span, finger, cubit, rod/pole, link, rope, ken, league) are given at their commonly accepted standard sizes — historical local values sometimes differed, so confirm against a primary source before relying on them for legal or historical work.
Frequently asked questions
- How many inch are in 1 millimetre?
- 1 millimetre = 0.03937008 inch (in).
- How do I convert millimetre to inch?
- Multiply the number of millimetre by 0.03937008. For example, 10 millimetre = 10 × 0.03937008 = 0.3937008 inch.
- How many millimetre are in 1 inch?
- 1 inch = 25.4 millimetre.
- Which is bigger, millimetre or inch?
- 1 inch equals 25.4 millimetre, so a inch is the larger unit.