IN to Millimeters Converter
Convert inches to millimeters instantly. Free online calculator.
Quick reference:
1 in = 25.4 mm
Tip: You can swap the direction to convert mm → in.
About Inches and Millimeters
Inches (in) is a unit of length in the metric system. It is commonly used for everyday measurements such as body height, fabric, furniture, and small distances.
Millimeters (mm) is a unit of length in the imperial/US customary system. It is widely used in the United States and in many industries (construction, screens, tools) where inches are standard.
Conversion formulas
- 1 in = 25.4 mm
- 1 mm = 0.03937007874 in
Tip: You can swap the direction if you want to convert mm → in.