Inches to Mm Converter

Use this free online converter to quickly convert inches to mm.

Converter

Enter a value in inches:

Formula: value * 25.4  |  Reverse: value / 25.4

1. How to Convert Inches to Mm

Multiply the inches value by 25.4.

Formula:

value * 25.4

Reverse formula (Mm → Inches):

value / 25.4

2. Conversion Example

Converting 10 inches to mm:

10 × 25.4 = 254.0 mm

10 inches = 254.0 mm

3. Did You Know?

One inch equals exactly 25.4 mm — a ratio fixed internationally in 1959 by the US, UK, Canada, Australia, New Zealand, and South Africa.

4. Frequently Asked Questions

• How many mm are in 1 inch?
  There are 25.4 mm in 1 inch.
• How do I convert inches to mm?
  Use the formula: value * 25.4. For example, 10 inches = 254.0 mm.
• Can I convert mm back to inches?
  Yes. Use the reverse formula: value / 25.4.