Inches to Millimeters Converter
Convert Inches to mm instantly. Free online converter.
Formula: 1 inch = 25.4 mm
Formula: mm = inches × 25.4 | inches = mm ÷ 25.4
Fractional Inches to Millimeters
| Fraction (in) | Decimal (in) | Millimeters (mm) |
|---|---|---|
| 1/16" | 0.0625 | 1.5875 |
| 1/8" | 0.125 | 3.175 |
| 3/16" | 0.1875 | 4.7625 |
| 1/4" | 0.25 | 6.35 |
| 5/16" | 0.3125 | 7.9375 |
| 3/8" | 0.375 | 9.525 |
| 7/16" | 0.4375 | 11.1125 |
| 1/2" | 0.5 | 12.7 |
| 9/16" | 0.5625 | 14.2875 |
| 5/8" | 0.625 | 15.875 |
| 11/16" | 0.6875 | 17.4625 |
| 3/4" | 0.75 | 19.05 |
| 13/16" | 0.8125 | 20.6375 |
| 7/8" | 0.875 | 22.225 |
| 15/16" | 0.9375 | 23.8125 |
| 1" | 1.0 | 25.4 |
Common Inches to Millimeters Conversions
| 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 | 127.0 mm |
| 6 in | 152.4 mm |
| 8 in | 203.2 mm |
| 10 in | 254.0 mm |
| 12 in | 304.8 mm |
| 18 in | 457.2 mm |
| 24 in | 609.6 mm |
| 36 in | 914.4 mm |
| 48 in | 1219.2 mm |
How to Convert Inches to Millimeters
To convert inches to millimeters, multiply by 25.4 (exact conversion).
For example, 3/4 inch = 0.75 × 25.4 = 19.05 mm.
This is an exact conversion — 1 inch is defined as exactly 25.4 millimeters.
💡 All calculations happen locally in your browser — no data is sent anywhere.