Miles per hour (abbreviated mph, MPH or mi/h) is an imperial and United States customary unit of speed expressing the number of statute miles covered in one hour. Although kilometres per hour is now the most widely used measure of speed, miles per hour remains the standard unit for speed limits in the United States, the United Kingdom, Antigua & Barbuda and Puerto Rico, although the latter two use kilometres for long distances.
| Definition | Relation to SI units |
|---|---|
≡ 1 mi/h |
| yard per hour | inch per minute | yard per minute | foot per minute | inch per hour | inch per second | mile per minute | foot per hour |
|---|---|---|---|---|---|---|---|
| 1 | 0.6 | 0.0166667 | 0.05 | 36 | 0.01 | 9.469696969697 × 10-6 | 3 |
| 1.6666667 | 1 | 0.0277778 | 0.0833333 | 60 | 0.0166667 | 1.5782828282828 × 10-5 | 5 |
| 60 | 36 | 1 | 3 | 2 160 | 0.6 | 0.0005682 | 180 |
| 20 | 12 | 0.3333333 | 1 | 720 | 0.2 | 0.0001894 | 60 |
| 0.0277778 | 0.0166667 | 0.0004630 | 0.0013889 | 1 | 0.0002778 | 2.6304713804714 × 10-7 | 0.0833333 |
| 100 | 60 | 1.6666667 | 5 | 3 600 | 1 | 0.0009470 | 300 |
| 105 600 | 63 360 | 1 760 | 5 280 | 3 801 600 | 1 056 | 1 | 316 800 |
| 0.3333333 | 0.2 | 0.0055556 | 0.0166667 | 12 | 0.0033333 | 3.1565656565657 × 10-6 | 1 |
| Symbol | Definition |
|---|---|
| ≡ | exactly equal |
| ≈ | approximately equal to |
| = | equal to |
| digits | indicates that digits repeat infinitely (e.g. 8.294 369 corresponds to 8.294 369 369 369 369 …) |
| 1 miles per hour | = 0.44704 meters per second |
| 2 miles per hour | = 0.89408 meters per second |
| 3 miles per hour | = 1.34112 meters per second |
| 4 miles per hour | = 1.78816 meters per second |
| 5 miles per hour | = 2.2352 meters per second |