Loading...
Convert inches (in) to millimeters (mm) instantly. Includes fractional-inch reference and chart.
An inch (in) is exactly 25.4 millimeters by international agreement (1959). To convert in to mm, multiply by 25.4; to convert mm to in, divide by 25.4.
1 in equals 25.400 mm.
| Inches (in) | Millimeters (mm) |
|---|---|
| 0.125 in | 3.175 mm |
| 0.25 in | 6.350 mm |
| 0.5 in | 12.700 mm |
| 0.75 in | 19.050 mm |
| 1 in | 25.400 mm |
| 1.5 in | 38.100 mm |
| 2 in | 50.800 mm |
| 3 in | 76.200 mm |
| 4 in | 101.60 mm |
| 5 in | 127.00 mm |
| 6 in | 152.40 mm |
| 8 in | 203.20 mm |
| 10 in | 254.00 mm |
| 12 in | 304.80 mm |
| 18 in | 457.20 mm |
| 24 in | 609.60 mm |
| 36 in | 914.40 mm |
| 48 in | 1219.20 mm |
| 60 in | 1524.00 mm |
| 100 in | 2540.00 mm |
Chart values use the exact factor 1 in = 25.4 mm.
Formula
mm = in × 25.4 | in = mm ÷ 25.4in = inch — US/UK customary unit (1 in = 25.4 mm, exact since 1959)
mm = millimeter — SI unit, 1/1000 of a meter
Worked Example
Convert 6 inches to millimeters
Did you know? Drill bit and screw size charts often list both inches and mm because manufacturers selling internationally need both standards. A 1/4-inch drill bit is exactly 6.35 mm; a #10 screw is roughly 4.83 mm.
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.