Inches to Millimeters Calculator

Inches to MM Reference Table

InchesMillimeters (mm)Centimeters (cm)Feet

Frequently Asked Questions

How many mm in an inch?

There are exactly 25.4 millimeters in one inch. This is the internationally defined conversion factor: 1 inch = 25.4 mm. This means 12 inches (1 foot) = 304.8 mm.

How to convert inches to mm?

To convert inches to millimeters, multiply the number of inches by 25.4. For example, 6 inches × 25.4 = 152.4 mm. To go the other way, divide millimeters by 25.4 to get inches.

What is 1 inch in mm?

1 inch is equal to 25.4 mm (millimeters) or 2.54 cm (centimeters). The inch is used in the US customary and imperial measurement systems, while the millimeter is the SI metric unit of length.