Formula.millimetres = inches × 25.4.
Relationship.1 in = 25.4 mm.
Worked example. 2 in = 50.8 mm.
Inches to Mm Converter.
1 in = 25.4 mm, so 2 in = 50.8 mm. Type any value below to convert inches to mm instantly.
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| mm | cm | m | km | in | ft | yd | mi | nmi |
|---|---|---|---|---|---|---|---|---|
| 0.0508 | 0.00508 | 0.0000508 | 5.080000e-8 | 0.002 | 0.0001666667 | 0.0000555556 | 3.156566e-8 | 2.742981e-8 |
| 0.508 | 0.0508 | 0.000508 | 5.080000e-7 | 0.02 | 0.0016666667 | 0.0005555556 | 3.156566e-7 | 2.742981e-7 |
| 5.08 | 0.508 | 0.00508 | 0.00000508 | 0.2 | 0.0166666667 | 0.0055555556 | 0.0000031566 | 0.000002743 |
| 50.8 | 5.08 | 0.0508 | 0.0000508 | 2 | 0.1666666667 | 0.0555555556 | 0.0000315657 | 0.0000274298 |
| 508 | 50.8 | 0.508 | 0.000508 | 20 | 1.666667 | 0.5555555556 | 0.0003156566 | 0.0002742981 |
| 5080 | 508 | 5.08 | 0.00508 | 200 | 16.666667 | 5.555556 | 0.0031565657 | 0.0027429806 |
| 50800 | 5080 | 50.8 | 0.0508 | 2000 | 166.666667 | 55.555556 | 0.0315656566 | 0.0274298056 |
How to convert inches to mm
inches to mm conversion table
| in | mm |
|---|---|
| 0.25 | 6.35 |
| 0.5 | 12.7 |
| 0.75 | 19.05 |
| 1 | 25.4 |
| 1.25 | 31.75 |
| 1.5 | 38.1 |
| 2 | 50.8 |
| 2.5 | 63.5 |
| 3 | 76.2 |
| 3.5 | 88.9 |
| 4 | 101.6 |
| 5 | 127 |
| 6 | 152.4 |
| 7 | 177.8 |
| 8 | 203.2 |
| 9 | 228.6 |
| 10 | 254 |
| 12 | 304.8 |
| 15 | 381 |
| 18 | 457.2 |
| 20 | 508 |
| 24 | 609.6 |
| 30 | 762 |
| 36 | 914.4 |
| 48 | 1219.2 |
Frequently Asked Questions
How do I convert inches to millimetres?
Multiply inches by 25.4. For example, 2 inches × 25.4 = 50.8 mm.
How many mm is 1 inch?
Exactly 25.4 mm, by international definition.
What is 1/4 inch in mm?
One quarter inch is 6.35 mm (0.25 × 25.4).
How precise is the inch-to-mm factor?
It is exact: the inch was defined as 25.4 mm in 1959, so there is no rounding error in the conversion itself.