The Speed Converter converts between kilometres per hour (km/h), miles per hour (mph), metres per second (m/s), feet per second (ft/s) and knots (kn). Use it when you read a foreign car review in mph, solve physics problems in m/s, follow cricket bowling speeds, check wind speeds in cyclone warnings (often in knots) or compare running paces.
How to use the speed converter
- Enter a speed.
- Choose the From and To units.
- Press Convert, or Swap units.
Speed conversion factors
| From | To | Multiply by |
|---|---|---|
| km/h | m/s | 5/18 ≈ 0.2778 |
| m/s | km/h | 18/5 = 3.6 |
| mph | km/h | 1.609344 |
| km/h | mph | 0.6214 |
| Knots | km/h | 1.852 |
| m/s | ft/s | 3.2808 |
| mph | m/s | 0.44704 |
Speed, distance and time
- Mumbai to Pune by expressway is about 150 km. At an average of 75 km/h, it takes 150 ÷ 75 = 2 hours.
- A train 300 m long passes a pole in 15 s. Speed = 300 ÷ 15 = 20 m/s = 20 × 18/5 = 72 km/h.
- Average speed for a round trip at 60 km/h out and 40 km/h back is the harmonic mean: 2 × 60 × 40 ÷ (60 + 40) = 48 km/h, not 50.
Everyday speed references
| What | km/h | mph | m/s |
|---|---|---|---|
| Walking | 5 | 3.1 | 1.4 |
| Recreational running (6 min/km) | 10 | 6.2 | 2.8 |
| Usain Bolt’s 100 m world record (average) | 37.6 | 23.4 | 10.4 |
| Typical city speed limit (India, cars) | 50 | 31 | 13.9 |
| Indian expressway limit (cars, typical) | 100 – 120 | 62 – 75 | 28 – 33 |
| Fast bowler (cricket) | 145 – 150 | 90 – 93 | 40 – 42 |
| Vande Bharat Express (design speed) | 180 | 112 | 50 |
| Commercial jet cruise | ~900 | ~560 | ~250 |
| Speed of sound (sea level, 20 °C) | 1,235 | 767 | 343 |
Speed limits vary by state, road type and vehicle class. Follow the posted signs.
Knots and nautical miles
One knot is one nautical mile per hour, which is 1.852 km/h. Ships, aircraft and meteorologists use knots because a nautical mile corresponds to one minute of latitude, which makes navigation on charts easy. The India Meteorological Department (IMD) classifies cyclones by maximum sustained wind speed in knots. For example, a Very Severe Cyclonic Storm has winds of 64–89 knots (118–166 km/h).
Pace vs speed for runners
Runners often use pace (minutes per km) instead of speed. To convert: pace (min/km) = 60 ÷ speed (km/h). 12 km/h = 5:00 min/km, and 10 km/h = 6:00 min/km. A 5:00 min/km pace finishes a 10K in 50 minutes and a half marathon in about 1 h 45 m.
Frequently asked questions
How do I convert km/h to m/s?
Multiply by 5/18, or divide by 3.6. For example, 90 km/h ÷ 3.6 = 25 m/s.
How do I convert mph to km/h?
Multiply by 1.609. 60 mph ≈ 96.6 km/h, and 70 mph ≈ 112.7 km/h.
What is a knot in km/h?
1 knot = 1.852 km/h = 1.151 mph. It is one nautical mile per hour.
What is the speed of sound in km/h?
About 1,235 km/h (343 m/s) in dry air at 20 °C at sea level. It changes with temperature.
How do I convert speed to running pace?
Divide 60 by your speed in km/h to get minutes per km. 12 km/h is a 5:00 min/km pace.