Length converter
Convert Inches to Millimeters (in to mm)
1 in = 25.4 mm. Reading metric drawings on imperial machines and gauging stock.
Inches to millimeters conversion table
| in | mm |
|---|---|
| 0.0625 in | 1.5875 mm |
| 0.125 in | 3.175 mm |
| 0.1875 in | 4.7625 mm |
| 0.25 in | 6.35 mm |
| 0.3125 in | 7.9375 mm |
| 0.375 in | 9.525 mm |
| 0.5 in | 12.7 mm |
| 0.625 in | 15.875 mm |
| 0.75 in | 19.05 mm |
| 0.875 in | 22.225 mm |
| 1 in | 25.4 mm |
| 1.25 in | 31.75 mm |
| 1.5 in | 38.1 mm |
| 2 in | 50.8 mm |
| 2.5 in | 63.5 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 |
| 36 in | 914.4 mm |
| 48 in | 1219.2 mm |
How to convert inches to millimeters
Multiply the value in inches by 25.4 to get millimeters. 1 in equals 25.4 mm, and 1 mm equals 0.03937 in.
About these units
The inch is the base dimension unit on US engineering drawings, defined exactly as 25.4 millimeters. Shop tolerances are usually expressed in decimal inches rather than fractions.
The millimeter is one thousandth of a meter and the default dimension unit on metric engineering drawings. Machined tolerances are commonly quoted in hundredths of a millimeter.
Common questions
How many millimeters are in an inch?
1 in equals 25.4 mm.
How do you convert inches to millimeters?
Use mm = in × 25.4. So 1 in = 25.4 mm, and to go back, 1 mm = 0.03937 in.
What is 0.25 in in mm?
0.25 in equals 6.35 mm.
What is 0.5 in in mm?
0.5 in equals 12.7 mm.