Conversion Calculator and Chart

You can use the calculator below to calculate inches to mm or calculate mm to inches.

(To calculate inches to mm or to calculate mm to inches, just input your measurement in this handy calculator!)

Did you know? The metric system originated in France in 1799 following the French Revolution. Decimal units had been used in many other countries previously. Although there have been many different measurements and the definitions of the units have been revised, the official system of measurements of most countries is the modern form of the metric system which is known as the "International System of Units".

The metric system was designed to have properties that make it easy to use and widely applicable, including units based on the natural world, decimal ratios, prefixes for multiples and sub-multiples, and a structure of base and derived units. It is also a coherent system, which means that its units do not introduce conversion factors not already present in equations relating quantities. It has a property called rationalization that eliminates certain constants of proportionality in equations of physics.

Although the metric system has changed and developed since its inception, its basic concepts have hardly changed. Designed for transnational use, it consisted of a basic set of units of measurement, now known as base unitsDerived units were built up from the base units using logical rather than empirical relationships while multiples and submultiples of both base and derived units were decimal-based and identified by a standard set of prefixes.

Here in the US, we've been struggling for years as most of the rest of the world has embraced the metric system while we remain primarily attached to using inches and feet as opposed to millimeters and meters.

Although there is a bit of a learning curve for us to switch over, it might well be worth it in the long run!