About this calculator
Type a number, choose the unit you have and the unit you want, and this converter gives you the answer at once, along with the same speed in every other unit it knows.
Every conversion factor is exact by definition wherever one exists, and each result shows the working so you can check it.
Worked examples
Real numbers, worked out by the same calculator. Press “Use these numbers” to try one above.
60 mph to km/h
- kilometres per hour (km/h)
- 96.56064 km/h
- metres per second (m/s)
- 26.8224 m/s
- knots (kn)
- 52.138574514 kn
- feet per second (ft/s)
- 88 ft/s
60 mph is 96.56064 km/h.
Show the working
- Change to the base unit (m/s): 60 mph × 0.44704 = 26.8224 m/s.
- Change to km/h: 26.8224 ÷ 0.277777777778 = 96.56064 km/h.
100 km/h to mph
- miles per hour (mph)
- 62.1371192237 mph
- metres per second (m/s)
- 27.7777777778 m/s
- knots (kn)
- 53.9956803456 kn
- feet per second (ft/s)
- 91.1344415281 ft/s
100 km/h is 62.1371192237 mph.
Show the working
- Change to the base unit (m/s): 100 km/h × 0.277777777778 = 27.7777777778 m/s.
- Change to mph: 27.7777777778 ÷ 0.44704 = 62.1371192237 mph.
10 kn to km/h
- kilometres per hour (km/h)
- 18.52 km/h
- metres per second (m/s)
- 5.14444444444 m/s
- miles per hour (mph)
- 11.5077944802 mph
- feet per second (ft/s)
- 16.878098571 ft/s
10 kn is 18.52 km/h.
Show the working
- Change to the base unit (m/s): 10 kn × 0.514444444444 = 5.14444444444 m/s.
- Change to km/h: 5.14444444444 ÷ 0.277777777778 = 18.52 km/h.
How to convert by hand
Every speed is stored in metres per second. Multiply by the size of the unit you have (in m/s), then divide by the size of the unit you want. For example, 60 mph × 0.44704 = 26.8224 m/s, which is 96.56064 km/h.
To go from m/s to km/h, multiply by 3.6; to go from km/h to m/s, divide by 3.6.
Conversion factors used
Each unit is stored as its size in m/s. The sizes below are the ones this converter uses.
| Unit | Size |
|---|---|
| metres per second (m/s) | 1 m/s |
| kilometres per hour (km/h) | 0.277777777778 m/s |
| miles per hour (mph) | 0.44704 m/s |
| knots (kn) | 0.514444444444 m/s |
| feet per second (ft/s) | 0.3048 m/s |
Common conversions
| From | To |
|---|---|
| 1 m/s | 3.6 km/h |
| 10 m/s | 22.3693629205 mph |
| 30 mph | 48.28032 km/h |
| 50 mph | 80.4672 km/h |
| 70 mph | 112.65408 km/h |
| 100 km/h | 62.1371192237 mph |
| 1 kn | 1.852 km/h |
| 1 kn | 1.15077944802 mph |
Knots
A knot is one nautical mile per hour: exactly 1.852 km/h, or about 1.1508 mph. It is the standard unit of speed for ships, aircraft and wind at sea.
Frequently asked questions
How many km/h is 70 mph?
70 mph is 112.65 km/h.
How do I convert m/s to km/h?
Multiply by 3.6.
How fast is one knot?
One knot is 1.852 km/h, or 1.1508 mph.
How accurate is this converter?
It uses the exact defined factors wherever they exist and shows up to 12 significant digits, so the results are accurate to far more digits than you will normally need.
Formulas tested against hand-worked answers. Last reviewed 29 September 2026. These calculators do arithmetic only; they are not financial, tax or legal advice.