📏 Length
millimeters to inches Converter
Convert millimeters to inches instantly. Includes a reference table and formula.
Quick answer: To convert millimeters to inches, multiply by 0.0393701. For example, 1 millimeters = 0.0393701 inches. Use the calculator below for any value.
millimeters to inches
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Common conversions
| millimeters | inches |
|---|
Formula:
How to convert millimeters to inches
1
Enter your value
Type the number of millimeters you want to convert into the left box. The result in inches appears instantly in the right box. You can also type into the right box to convert in the other direction.
2
Use the swap button
Click the ⇄ Swap button to reverse the conversion — inches to millimeters. Your current value carries across so you don't have to re-enter anything.
3
About millimeters and inches
millimeters and inches are both length measurements. Use this converter to switch between them instantly.
💡 Did you know?
1 mm = 0.03937 inches. Engineers use 25.4 mm/inch as an exact factor (since 1959). In trades, 1 mm ≈ 1/25 inch is a usable approximation.
📊 Common conversions at a glance
| millimeters | inches |
|---|---|
| 1 | 0.03937 |
| 5 | 0.1969 |
| 10 | 0.3937 |
| 15 | 0.5906 |
| 20 | 0.7874 |
| 25 | 0.9843 |
Reviewed for 2026. millimeters ↔ inches conversion factor verified against published reference data. Built by a UK-based qualified primary teacher and FA Level 2 coach as part of 247QuickTools' free utility-tools project.