Inches to millimeters converter

Provide a length below to convert inches (in) to millimeters (mm). For the reverse direction, visit the millimeters to inches converter.

1 inch equals exactly 25.4 millimeters. This fixed relationship was established by the international agreement defining the yard and pound in 1959.

To convert inches to millimeters, multiply the measurement in inches by 25.4. To convert millimeters to inches, divide the length in millimeters by 25.4.

Inch

Definition: The inch (symbol: in) is a length unit within imperial and US customary systems, defined precisely as 25.4 millimeters with 12 inches comprising one foot.

History: Inches have ancient origins with varying definitions across regions and time periods. The modern international inch was standardized in 1959 to maintain consistency in measurements across English-speaking nations.

Current use: Inches are extensively used in the United States, Canada, and the United Kingdom for general measurements, construction, and manufacturing. The unit also appears globally in electronics and display screen specifications.

Millimeter

Definition: A millimeter (symbol: mm) is a metric unit equal to 0.001 meters or one-thousandth of a meter, making it suitable for precise small-scale measurements.

History: Derived from the meter using the "milli-" prefix (meaning one-thousandth), the millimeter became part of the metric system developed in France during the late 1700s. This systematic naming convention simplifies conversions within the metric system.

Current use: Millimeters serve as a standard unit for precision measurements worldwide, particularly in engineering, manufacturing, and technical specifications. They bridge the gap between centimeters and micrometers for practical applications.

Inch to Millimeter Conversion Table
Inch [in]Millimeter [mm]
0.01 in0.254 mm
0.1 in2.54 mm
1 in25.4 mm
2 in50.8 mm
3 in76.2 mm
5 in127 mm
10 in254 mm
20 in508 mm
50 in1270 mm
100 in2540 mm
1000 in25400 mm