How do I convert mm to inches?

Divide the number of millimeters by 25.4, because 1 inch equals 25.4 mm. For example, 25.4 mm / 25.4 = 1 inch. The tool does this automatically as you type.

How many inches is 1 mm?

1 millimeter equals about 0.03937 inches. Conversely, 1 inch equals exactly 25.4 millimeters.

How accurate is the conversion?

The conversion uses the standard, exact factor 1 inch = 25.4 millimeters (the international inch). Results are shown to several decimal places for precision, so they are suitable for both everyday and technical use.

Can I convert inches to millimeters?

Yes - enter a value in either field and the other unit updates automatically. To convert inches to millimeters, multiply the inches by 25.4.

What is the difference between mm and cm converters?

10 mm = 1 cm, so the numbers differ by a factor of 10. Use this tool for small lengths (drawings, hardware, thickness). Use the CM to Inches Converter for larger measurements like clothing or screen sizes.

Does my measurement leave the device?

No. The MM to Inches Converter runs entirely in your browser. Values are not uploaded or stored on a server.

Converter Tools

MM to Inches Converter

Convert millimeters to inches (and inches back to millimeters) instantly with the exact factor 1 inch = 25.4 mm.

Millimeters

= 0.3937 inches

Inches

= 10 mm

About MM to Inches Converter

Convert millimeters to inches (and inches back to millimeters) instantly with the exact factor 1 inch = 25.4 mm. Type a value in either field and the other updates automatically, with results to several decimal places. It is perfect for engineering drawings, 3D-print models, jewelry, screw and hardware sizes, phone and laptop thickness, and any spec that mixes metric millimeters with imperial inches. Everything runs in your browser.

How to Use MM to Inches Converter

Enter a value in the millimeters field to convert to inches.
Or enter a value in the inches field to convert to millimeters.
The other unit updates automatically in both directions.
Copy the converted value for your measurement or spec.

MM to Inches Converter Examples

25.4 mm to inches

25.4 mm = 1 inch exactly.

10 mm to inches

10 mm = 0.3937 inches (10 mm is 1 cm).

100 mm to inches

100 mm = 3.937 inches.

Phone thickness

A 7.8 mm phone is about 0.307 inches thick.

Read the full guide

How to Use MM to Inches Converter: Complete Guide (2026) - 5 min read

Frequently Asked Questions about MM to Inches Converter

How do I convert mm to inches?: Divide the number of millimeters by 25.4, because 1 inch equals 25.4 mm. For example, 25.4 mm / 25.4 = 1 inch. The tool does this automatically as you type.
How many inches is 1 mm?: 1 millimeter equals about 0.03937 inches. Conversely, 1 inch equals exactly 25.4 millimeters.
How accurate is the conversion?: The conversion uses the standard, exact factor 1 inch = 25.4 millimeters (the international inch). Results are shown to several decimal places for precision, so they are suitable for both everyday and technical use.
Can I convert inches to millimeters?: Yes - enter a value in either field and the other unit updates automatically. To convert inches to millimeters, multiply the inches by 25.4.
What is the difference between mm and cm converters?: 10 mm = 1 cm, so the numbers differ by a factor of 10. Use this tool for small lengths (drawings, hardware, thickness). Use the CM to Inches Converter for larger measurements like clothing or screen sizes.
Does my measurement leave the device?: No. The MM to Inches Converter runs entirely in your browser. Values are not uploaded or stored on a server.

CM to Inches Converter

Convert centimeters to inches and inches to centimeters instantly. Free online cm to inches converter using 1 inch = 2.54 cm, with precise results in both directions.

Pixels to Inches Converter

Convert pixels to inches and inches to pixels at any DPI. Free px to inches calculator for web (96 DPI) and print (300 DPI).