📏 Millimeters to Inches Converter
Convert millimeters (mm) to inches (in) instantly, with the formula, a worked example and a conversion table.
Quick answer: 1 millimeter (mm) = 0.039370079 inches (in). Formula: in = mm × 0.039370079.
Updated · Free · No sign-up · Works on any device
Millimeters to Inches Converter inputs
Result
Millimeters to Inches conversion table
| Millimeters (mm) | Inches (in) |
|---|---|
| 0.1 mm | 0.0039370079 in |
| 0.5 mm | 0.019685039 in |
| 1 mm | 0.039370079 in |
| 2 mm | 0.078740157 in |
| 3 mm | 0.11811024 in |
| 5 mm | 0.19685039 in |
| 10 mm | 0.39370079 in |
| 20 mm | 0.78740157 in |
| 25 mm | 0.98425197 in |
| 50 mm | 1.9685039 in |
| 100 mm | 3.9370079 in |
| 1,000 mm | 39.370079 in |
Other length conversions
mm to cmmm to mmm to kmmm to inmm to ftmm to ydmm to mimm to nmi
How to convert millimeters to inches
Multiply the number of millimeters by 0.039370079 to get inches: in = mm × 0.039370079.
Example: 5 mm = 0.19685039 in.
The millimeter (mm) and the inch (in) are both units of length. Need the opposite direction? Use the in to mm converter.
Popular conversions
Centimeter to InchInch to CentimeterFoot to MeterMeter to FootKilometer to MileMile to KilometerKilogram to PoundPound to KilogramCelsius to FahrenheitFahrenheit to CelsiusMilliliter to US cupUS cup to MilliliterLiter to US gallonUS gallon to LiterGram to OunceOunce to GramSquare foot to Square meterAcre to HectareKilometer per hour to Mile per hourMile per hour to Kilometer per hourMegabyte to GigabytePound per square inch to Bar
Metric and imperial units
The metric system (SI) is used by almost every country and by science worldwide. Its units scale by powers of ten – 1 kilometer is 1,000 meters, 1 meter is 100 centimeters – which makes conversions inside the system easy. The imperial and US customary systems (inches, feet, pounds, gallons) are still used daily in the United States and partly in the UK.
Since 1959 the inch has been defined as exactly 2.54 centimeters and the pound as exactly 0.45359237 kilograms, so conversions between the two systems are exact. Note that a US gallon (3.785 L) and an imperial gallon (4.546 L) are different – choose the right one above.
This converter covers 10 categories and 66 units: length, weight, temperature, volume, area, speed, time, data, energy, pressure.
Frequently asked questions
How many inches are in a millimeter?
1 millimeter = 0.039370079 inches.
How do I convert millimeters to inches?
Use the formula in = mm × 0.039370079. For example, 5 mm = 0.19685039 in.
How do I convert inches back to millimeters?
1 inch = 25.4 millimeters. Use the in to mm converter linked on this page.
Are these conversions exact?
Yes – all factors use the internationally defined values (for example 1 inch = 2.54 cm exactly, 1 pound = 0.45359237 kg exactly). Results are rounded to 8 significant digits for display.