Advertisement

Speed Calculator

Calculate speed, distance, or time using the formula Speed = Distance ÷ Time. Choose what you want to find, enter the other two values, and get results in multiple speed units instantly.

Speed, Distance & Time Formulas

Speed: S = D ÷ T
Distance: D = S × T
Time: T = D ÷ S

Common Speed Reference Points

Walking average: 5 km/h (3.1 mph)
Running average: 12 km/h (7.5 mph)
City car limit: 50 km/h (31 mph)
Highway car: 120 km/h (75 mph)
Speed of sound: 1,235 km/h (Mach 1)
Speed of light: 1,079,252,848 km/h

Frequently Asked Questions

Speed is a scalar quantity — it only has magnitude (e.g. 60 km/h). Velocity is a vector quantity — it has both magnitude and direction (e.g. 60 km/h north). This calculator computes scalar speed. In physics, average speed = total distance / total time, while average velocity = displacement / time.

Mach number is the ratio of an object's speed to the local speed of sound. Mach 1 is approximately 343 m/s (1,235 km/h / 767 mph) at sea level and 20°C. Mach 2 means twice the speed of sound. Commercial aircraft cruise around Mach 0.85, while supersonic jets exceed Mach 1.

Average walking speed is about 5 km/h (3.1 mph). Average jogging is around 8–12 km/h (5–7.5 mph). Elite sprint speed is around 37–44 km/h (23–27 mph). Usain Bolt's top recorded speed was 44.72 km/h (27.8 mph).

To convert km/h to mph, divide by 1.60934. For example, 100 km/h ÷ 1.60934 ≈ 62.14 mph. To go the other direction, multiply mph by 1.60934.

A knot is a unit of speed equal to one nautical mile per hour, where one nautical mile = 1,852 metres. It is widely used in maritime and aviation contexts. 1 knot = 1.852 km/h = 1.151 mph.

Related Calculators