Speed, Distance & Time Calculator
Calculate speed, distance, or time when you know any two of the three values.
The relationship between speed, distance, and time is one of the most fundamental formulas in physics and everyday life: Speed = Distance / Time. Rearranged, Distance = Speed x Time and Time = Distance / Speed.
This calculator solves for whichever value you leave blank. Enter any two of the three variables and the third is computed automatically. Units are handled so you can mix kilometers, miles, and hours freely.
Practical uses include estimating arrival times for road trips, calculating average speed from GPS data, and planning athletic training distances. Remember that this assumes constant speed — real-world travel includes stops, acceleration, and varying terrain.