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ConvertersLength Converter

Inches to MM Conversion Calculator

Converting imperial inches to metric millimeters is fundamental across CAD design, 3D printing, and mechanical engineering.

Converted Result
25.4 mm
1 in = 25.4 mm

Equivalent Values in Other Units

Meter
0.0254 m
Kilometer
0 km
Centimeter
2.54 cm
Mile
0 mi
Yard
0.0278 yd
Foot
0.0833 ft
Nautical Mile
0 NM
Reverse Conversion Available
MM to Inches Converter (Millimeters to Inches)
Convert mm to in
Formula & Calculation Method

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

Conversion Formula
Millimeters = Inches × 25.4
Step-by-Step Worked Example

To convert 1/2 inch (0.5 in) to millimeters: 0.5 × 25.4 = 12.7 mm.

Inch to Millimeter Conversion Table

Quick reference values for common inch measurements.

1 in = 25.4 mm
Inch (in)Millimeter (mm)
0.125 in3.175 mm
0.25 in6.35 mm
0.5 in12.7 mm
0.75 in19.05 mm
1 in25.4 mm
2 in50.8 mm
3 in76.2 mm
4 in101.6 mm
5 in127 mm
6 in152.4 mm
8 in203.2 mm
10 in254 mm
12 in304.8 mm

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Frequently Asked Questions

There are exactly 25.4 millimeters in 1 inch.