Loading...
Convert millimeters (mm) to inches (in) instantly. Full chart with formula and reverse direction.
A millimeter (mm) is 1/1000 of a meter; an inch (in) is defined as exactly 25.4 mm. To convert mm to in, divide by 25.4; to convert in to mm, multiply by 25.4.
1 mm equals 0.0394 in.
| Millimeters (mm) | Inches (in) |
|---|---|
| 1 mm | 0.0394 in |
| 2 mm | 0.0787 in |
| 3 mm | 0.1181 in |
| 5 mm | 0.1969 in |
| 6 mm | 0.2362 in |
| 8 mm | 0.3150 in |
| 10 mm | 0.3937 in |
| 12 mm | 0.4724 in |
| 15 mm | 0.5906 in |
| 20 mm | 0.7874 in |
| 25 mm | 0.9843 in |
| 30 mm | 1.181 in |
| 40 mm | 1.575 in |
| 50 mm | 1.969 in |
| 75 mm | 2.953 in |
| 100 mm | 3.937 in |
| 150 mm | 5.906 in |
| 200 mm | 7.874 in |
| 254 mm | 10.000 in |
| 500 mm | 19.685 in |
| 1000 mm | 39.370 in |
Chart values use the exact factor 1 in = 25.4 mm, rounded for display.
Formula
in = mm ÷ 25.4 | mm = in × 25.4mm = millimeter — SI unit, 1/1000 of a meter (1 mm = 0.1 cm)
in = inch — US/UK customary unit (1 in = 25.4 mm, exact since 1959)
Worked Example
Convert 100 mm to inches
Did you know? Precision engineering and manufacturing tend to use millimeters even in the US, because mm avoid the fractions (1/8 inch, 3/16 inch) that imperial measurement requires. Most engineering CAD software defaults to mm for this reason.
Sources
Convert between square feet, square meters, acres, hectares, and more with quick reference tables.
Convert bra sizes between US, UK, EU, AU, and FR/IT systems. Enter band and cup size to see all equivalents.
Convert centimeters (cm) to inches (in) instantly. Full chart from 1–250 cm with formula and reverse direction.
Convert cups to US quarts. Chart, formula, and reverse direction.
Convert between joules, calories, kWh, BTU, and more. Includes food calorie conversions.
Convert feet (ft) to meters (m) instantly. Chart, height conversions, and reverse direction.