Inches to Millimeters Converter
Convert in to mm instantly — and see every other length unit at once.
1 in=25.4 mm
1 in in every unit
Millimeters
25.4mm
Centimeters
2.54cm
Meters
0.0254m
Kilometers
2.5400e-5km
Inchesfrom
1in
Feet
0.083333ft
Yards
0.027778yd
Miles
1.5783e-5mi
Nautical miles
1.3715e-5nmi
Common Inches to Millimeters conversions
| Inches (in) | Millimeters (mm) |
|---|---|
| 0.25 in | 6.35 mm |
| 0.5 in | 12.7 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 |
| 8 in | 203.2 mm |
| 10 in | 254 mm |
| 12 in | 304.8 mm |
| 24 in | 609.6 mm |
The formula
Inches are used in the US and UK for screen sizes, hardware, and small distances.
Millimeters are the metric unit for small, precise lengths — engineering, manufacturing, and rainfall.
Worked examples
1 in→25.4 mm— 1 inch
Apply in × 25.4 with input = 1. Result: 25.4 mm.
0.5 in→12.7 mm— Half inch
Apply in × 25.4 with input = 0.5. Result: 12.7 mm.
12 in→304.8 mm— 1 foot
Apply in × 25.4 with input = 12. Result: 304.8 mm.
4 in→101.6 mm— 4 inches
Apply in × 25.4 with input = 4. Result: 101.6 mm.
FAQ
How do I convert Inches to Millimeters?
Use the formula: mm = in × 25.4. You can also use the converter above — type any value and the result updates instantly.
Where are Inches used?
Inches are used in the US and UK for screen sizes, hardware, and small distances.
Where are Millimeters used?
Millimeters are the metric unit for small, precise lengths — engineering, manufacturing, and rainfall.
How do I convert Millimeters back to Inches?
Use the Millimeters to Inches converter.