Convert millimeters to inches using the exact relationship of 25.4 millimeters per inch. Enter any millimeter value to receive a precise inch equivalent result instantly.
Converted value = Source value × Conversion factor
For affine conversions such as temperature, an offset is also applied.The tool applies the relevant factor or temperature offset to the source value. Currency outputs require a current exchange-rate source, while cooking volume-to-weight conversions can vary by ingredient density and measuring method.
Convert millimeters to inches by dividing the millimeter value by 25.4. One inch is exactly equal to 25.4 millimeters, so 1 millimeter equals approximately 0.03937 inches. Enter a length in millimeters (mm) into the converter to calculate the equivalent measurement in inches (in).
To convert millimeters to inches, divide the length in millimeters by 25.4.
Conversion factor: 1 inch = exactly 25.4 millimeters
Therefore: 1 millimeter = approximately 0.0393701 inches
The result can also be calculated by multiplying the millimeter value by approximately 0.0393701.
Inches = Millimeters ÷ 25.4
Alternatively:
Inches = Millimeters × 0.0393701
The relationship of 1 inch to 25.4 millimeters is exact. The decimal value 0.0393701 is rounded, so dividing by 25.4 generally provides the most reliable result.
Convert 50 millimeters to inches:
Rounded to two decimal places, 50 millimeters is approximately 1.97 inches.
| Millimeters (mm) | Inches (in) |
|---|---|
| 1 mm | 0.03937 in |
| 2 mm | 0.07874 in |
| 3 mm | 0.11811 in |
| 5 mm | 0.19685 in |
| 10 mm | 0.39370 in |
| 15 mm | 0.59055 in |
| 20 mm | 0.78740 in |
| 25 mm | 0.98425 in |
| 25.4 mm | 1.00000 in |
| 30 mm | 1.18110 in |
| 40 mm | 1.57480 in |
| 50 mm | 1.96850 in |
| 75 mm | 2.95276 in |
| 100 mm | 3.93701 in |
| 150 mm | 5.90551 in |
| 200 mm | 7.87402 in |
| 250 mm | 9.84252 in |
| 300 mm | 11.81102 in |
| 500 mm | 19.68504 in |
| 1,000 mm | 39.37008 in |
For a quick estimate, 10 millimeters is about 0.39 inches, 100 millimeters is about 3.94 inches, and 1,000 millimeters is about 39.37 inches.
A millimeter is a metric unit used to measure length or distance. Its symbol is mm. It is part of the International System of Units and equals one-thousandth of a meter. Millimeters are commonly used for small dimensions, material thicknesses, hardware sizes, engineering measurements, and product specifications.
An inch is a unit of length in the United States customary and imperial measurement systems. Its symbol is in, and it may also be represented by a double-prime mark. One inch is exactly 25.4 millimeters. Inches are commonly used in the United States for dimensions, screen sizes, construction materials, and personal measurements.
Divide the millimeter measurement by 25.4. The formula is inches = millimeters ÷ 25.4.
One millimeter equals approximately 0.0393701 inches. This decimal is rounded because its digits continue indefinitely.
Divide 10 by 25.4. The result is approximately 0.39370 inches, which is commonly rounded to 0.39 inches.
Exactly 25.4 millimeters make one inch. This is a defined conversion relationship and is not an approximation.
The appropriate precision depends on the application. Two decimal places may be sufficient for general estimates, while manufacturing and engineering measurements may require three or more decimal places.
Multiply the number of inches by 25.4. For example, 2 inches × 25.4 equals exactly 50.8 millimeters.
Enter a known source value, confirm the direction of conversion and compare the result with the level of precision required. Keep extra decimal places for technical work and round only at the final step.
The converter provides results in decimal inches. Some construction, woodworking, and hardware measurements are written as inch fractions. A decimal result can be rounded to the nearest commonly used fraction.
| Decimal Inch | Approximate Fraction | Equivalent Millimeters |
|---|---|---|
| 0.0625 in | 1/16 in | 1.5875 mm |
| 0.125 in | 1/8 in | 3.175 mm |
| 0.1875 in | 3/16 in | 4.7625 mm |
| 0.25 in | 1/4 in | 6.35 mm |
| 0.375 in | 3/8 in | 9.525 mm |
| 0.5 in | 1/2 in | 12.7 mm |
| 0.625 in | 5/8 in | 15.875 mm |
| 0.75 in | 3/4 in | 19.05 mm |
| 0.875 in | 7/8 in | 22.225 mm |
| 1 in | 1 in | 25.4 mm |
The number of decimal places needed depends on how the converted measurement will be used:
A rounded conversion should not imply greater accuracy than the original measurement. For example, a roughly measured value of 50 mm should not automatically be treated as an exact 1.96850-inch dimension.
Millimeters, centimeters, and meters belong to the metric system and use powers of ten:
When converting a larger metric measurement, it may be convenient to convert millimeters to centimeters or meters first. However, dividing the original millimeter value directly by 25.4 produces the inch result without an additional step.