Millimeters to Inches
A millimeter is one thousandth of a meter, the standard unit on rulers and rainfall gauges worldwide. An inch is exactly 2.54 centimeters, used for screen sizes, paper formats, and everyday measurements in the US. 1 mm equals ≈0.0393701 in, so converting between them is a matter of multiplying by that fixed factor — type any value into the converter below and both sides update instantly as you type.
Both units belong to length, measured here against length's base unit (m) — every other length unit on this site converts through that same reference point, which is why the table below can also be read as a quick cross-check against nearby values.
Formula
in = mm × ≈0.0393701
mm = in × 25.4
Worked example: 5 mm × ≈0.0393701 = ≈0.19685 in.
Conversion table
| Millimeter (mm) | Inch (in) |
|---|---|
| 1 mm | ≈0.0393701 in |
| 2 mm | ≈0.0787402 in |
| 3 mm | ≈0.11811 in |
| 5 mm | ≈0.19685 in |
| 10 mm | ≈0.393701 in |
| 20 mm | ≈0.787402 in |
| 25 mm | ≈0.984252 in |
| 50 mm | ≈1.9685 in |
| 100 mm | ≈3.93701 in |
| 250 mm | ≈9.84252 in |
| 500 mm | ≈19.685 in |
| 1,000 mm | ≈39.3701 in |
Frequently asked
- How many Inches in a millimeter?
- 1 mm equals ≈0.0393701 in.
- How do I convert Millimeters to Inches?
- Multiply the value in mm by ≈0.0393701 to get in. The converter above does this instantly as you type.
- Is the conversion exact?
- Yes — Millimeter and Inch are both defined by a fixed conversion factor to length's base unit (m), so the result shown is exact to the precision displayed, not an approximation.