Speed, distance & time calculator
Solve for speed, distance or time from the other two values, with explicit units and a pace you can inspect.
Choose the unknown. Enter positive values for the other two quantities.
The selected answer row remains visible so you can choose its output unit.
Equivalent values use the same constant-rate result; rounding affects display only.
Included
- Solving speed = distance ÷ time
- Solving distance = speed × time
- Solving time = distance ÷ speed
- Conversions between metric, imperial and nautical units
- Optional minutes-per-kilometre or minutes-per-mile pace
Not included
- Acceleration, changing speed or rest stops
- Traffic, terrain, weather and route selection
- Arrival-time predictions or time-zone changes
- Fuel, energy or journey-cost estimates
What this means
Speed, distance and time describe the same constant-rate relationship. Once two values are known, the third follows from one of three reciprocal formulas. This calculator converts every known value to metres and seconds before solving, then converts the answer into the unit you selected.
The result is an average-speed model. A journey that covers 100 kilometres in two hours has an average speed of 50 km/h even if the actual speed changed along the way or the journey included stops.
Pace expresses the reciprocal of speed as time per unit distance. It is useful for running and walking, but it does not add route, elevation or fitness assumptions.
Formula & worked example
speed = distance ÷ time distance = speed × time time = distance ÷ speed pace = time ÷ distance
Calculate the average speed for 10 km completed in 48 minutes
- Distance
- 10 km
- Time
- 48 min = 0.8 h
- Average speed
- 10 ÷ 0.8 = 12.5 km/h
The average speed is 12.5 km/h and the pace is 4:48 per kilometre.