Convert inchs to millimeters
Convert inchs to millimeters, with the formula and a quick reference table.
Result
≈ 25 5/12 millimeters · 1 in = 25.4 mm
All length units
| Unit | Value | Symbol |
|---|---|---|
| 25,400,000 | nm | |
| 25,400 | µm | |
| 25.4 | mm | |
| 2.54 | cm | |
| 0.0254 | m | |
| 0.0000254 | km | |
| 1 | in | |
| 0.083333333 | ft | |
| 0.027777778 | yd | |
| 0.000015782828 | mi | |
| 0.000013714903 | nmi | |
| 0.00012626263 | fur | |
| 0.013888889 | ftm | |
| 0.25 | hh | |
| 1,000 | mil | |
| 1.697885 × 10^13 | AU | |
| 2.684782 × 10^18 | ly | |
| 8.231579 × 10^19 | pc |
inchs to millimeters at a glance
| in | mm |
|---|---|
| 1 | 25.4 |
| 2 | 50.8 |
| 3 | 76.2 |
| 4 | 101.6 |
| 5 | 127 |
| 10 | 254 |
| 25 | 635 |
| 50 | 1,270 |
| 100 | 2,540 |
Other length conversions
How it works
Every unit in this dimension is defined as a ratio to one base unit — the meter. Converting is therefore two multiplications: into the base unit, then out of it.
1 in = 25.4 mm Rounding
Results are rounded to 8 significant figures, adjustable with the slider above. Exact factors are used internally, so chaining conversions does not accumulate error.
Sources
Conversion factors follow NIST Special Publication 811 (Guide for the Use of the International System of Units) and the BIPM SI Brochure, 9th edition. Every factor is checked by an automated round-trip test on each build.