Length Converter
Metric and imperial distances.
Conversion
Inches to Millimeters Converter
1 inch = 25.4 mm. Enter any value to convert inches (in) to millimeters (mm), or use the table below for common values.
Formula
mm = in × 25.4
Example: 10 in = 254 mm. To convert the other way, use in = mm × 0.03937007874.
Quick mental estimate: multiply by about 25.
Inches to Millimeters conversion table
| Inches (in) | Millimeters (mm) |
|---|---|
| 1 in | 25.4 mm |
| 2 in | 50.8 mm |
| 3 in | 76.2 mm |
| 4 in | 101.6 mm |
| 5 in | 127 mm |
| 6 in | 152.4 mm |
| 7 in | 177.8 mm |
| 8 in | 203.2 mm |
| 9 in | 228.6 mm |
| 10 in | 254 mm |
| 15 in | 381 mm |
| 20 in | 508 mm |
| 25 in | 635 mm |
| 30 in | 762 mm |
| 40 in | 1,016 mm |
| 50 in | 1,270 mm |
| 75 in | 1,905 mm |
| 100 in | 2,540 mm |
| 250 in | 6,350 mm |
| 500 in | 12,700 mm |
| 1,000 in | 25,400 mm |
About inches and millimeters
The inch is defined as exactly 2.54 centimeters (international agreement of 1959). It is used in the US and UK for screen sizes, lumber, fasteners and body height.
The millimeter is one thousandth of a meter. It is the standard unit on engineering drawings, for rainfall, and for screen, sheet and tool sizes.
Other Length conversions
Millimeters → InchesReverse conversionCentimeters → Millimeterscm → mmMeters → Millimetersm → mmKilometers → Millimeterskm → mmInches → Centimetersin → cmInches → Metersin → mInches → Kilometersin → kmInches → Feetin → ftInches → Yardsin → ydInches → Milesin → miInches → Nautical Milesin → nmiFeet → Millimetersft → mmYards → Millimetersyd → mmMiles → Millimetersmi → mmNautical Miles → Millimetersnmi → mm
Frequently asked questions
How do I convert inches to millimeters?
Use the formula mm = in × 25.4. For example, 10 in = 254 mm.
What is 1 inch in millimeters?
1 in = 25.4 mm.
How do I convert millimeters back to inches?
Use in = mm × 0.03937007874. 1 mm = 0.03937007874 in.