How many mm in 1 inches?
The answer is 25.4.
We assume you are converting between millimetre and inch.
You can view more details on each measurement unit:
mm or
inches
The SI base unit for length is the metre.
1 metre is equal to 1000 mm, or 39.370078740157 inches.
Note that rounding errors may occur, so always check the results.
Use this page to learn how to convert between millimetres and inches.
Type in your own numbers in the form to convert the units!

Quick conversion chart of mm to inches

1 mm to inches = 0.03937 inches

10 mm to inches = 0.3937 inches

20 mm to inches = 0.7874 inches

30 mm to inches = 1.1811 inches

40 mm to inches = 1.5748 inches

50 mm to inches = 1.9685 inches

100 mm to inches = 3.93701 inches

200 mm to inches = 7.87402 inches

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inches to mm, or enter any two units below:

A millimetre (American spelling: millimeter, symbol mm) is one thousandth of a metre, which is the International System of Units (SI) base unit of length. The millimetre is part of a metric system. A corresponding unit of area is the square millimetre and a corresponding unit of volume is the cubic millimetre.

Definition: Inch

An inch is the name of a unit of length in a number of different systems, including Imperial units, and United States customary units. There are 36 inches in a yard and 12 inches in a foot. The inch is usually the universal unit of measurement in the United States, and is widely used in the United Kingdom, and Canada, despite the introduction of metric to the latter two in the 1960s and 1970s, respectively. The inch is still commonly used informally, although somewhat less, in other Commonwealth nations such as Australia; an example being the long standing tradition of measuring the height of newborn children in inches rather than centimetres. The international inch is defined to be equal to 25.4 millimeters.

Metric conversions and more

ConvertUnits.com provides an online conversion calculator for all types of measurement units. You can find metric conversion tables for SI units, as well as English units, currency, and other data. Type in unit symbols, abbreviations, or full names for units of length, area, mass, pressure, and other types. Examples include mm, inch, 70 kg, 150 lbs, US fluid ounce, 6'3", 10 stone 4, cubic cm, metres squared, grams, moles, feet per second, and many more!