Inches to Millimeters

Convert inches (in) to millimeters (mm) with formulas, examples, and conversion tables.

Inches (in)

Millimeters (mm)

1 in = 25.4 mm

Full precision:25.4 mm

Step-by-Step Solution

To convert 1 inches to millimeters, we multiply by 25.4 because one inch equals exactly 25.4 millimeters.

1 inch = 25.4 millimeters

Since each inch contains 25.4 millimeters, we multiply our value by this factor:

1 × 25.4 = 25.4 millimeters

So 1 inches = 25.4 millimeters.

✓Quick check: 25.4 ÷ 25.4 = 1 inches

How to Convert Inches to Millimeters

To convert inches to millimeters, multiply the value by 25.4.

Millimeters = Inches × 25.4

1 inch = 25.4 millimeters

Tip: To convert millimeters back to inches, divide by 25.4.

Example 1: 1 in = 25.4 mm
1 × 25.4 = 25.4

Example 2: 5 in = 127 mm
5 × 25.4 = 127

Example 3: 10 in = 254 mm
10 × 25.4 = 254

Unit	1 in =
Inches to Kilometers	0.000025 km
Inches to Meters	0.0254 m
Inches to Centimeters	2.54 cm
Inches to Millimeters	25.4 mm
Inches to Micrometers	25400 μm
Inches to Nanometers	25400000 nm
Inches to Miles	0.000016 mi
Inches to Yards	0.027778 yd
Inches to Feet	0.083333 ft
Inches to Nautical Miles	0.000014 nmi
Inches to Fathoms	0.013889 ftm
Inches to Light Years	2.68e-18 ly
Inches to Astronomical Units	1.7e-13 AU
Inches to Parsecs	8.23e-19 pc
Inches to Angstroms	254000000 Å
Inches to Planck Lengths	1.57e+33 ℓP
Inches to Rods	0.005051 rd

The inch (in) is a unit of length in the imperial system. One inch equals 0.0254 meters.

The millimeter (mm) is a unit of length in the metric system. One millimeter equals 0.001 meters.