Free Online Calculators
Inch → Millimeter
1 inch = 25.4 mm, and 1 millimeter = 0.0393701 in.
Reverse: MM to Inches Converter
Threads, pipes and wrench sizes are often specified in fractional inches, while parts are machined in millimeters. Enter 0.25 for a quarter inch or 0.375 for three eighths.
| in | mm |
|---|---|
| 0.125 in | 3.175 mm |
| 0.25 in | 6.35 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 |
| 18 in | 457.2 mm |
| 24 in | 609.6 mm |
| 36 in | 914.4 mm |
| 48 in | 1,219.2 mm |
Calculated with the same formula as the converter, rounded to six significant digits.
1 inch equals 25.4 mm. Formula: mm = in × 25.4.
10 in = 254 mm, because 10 × 25.4 = 254.
1 millimeter equals 0.0393701 in. To convert back, divide by 25.4.