Speed–Distance–Time Calculator

About this calculator

This calculator uses the fixed relationship between speed, distance and time — distance equals speed multiplied by time — to solve for whichever one of the three values you don't already know, as long as the other two are entered. Because the formula can be rearranged three different ways, the same tool works whether you're missing the speed, the distance, or the time.

It is a staple of physics and math coursework, where students plug in two known values to find the third and check their manual algebra, but it also solves everyday practical questions: estimating how long a trip will take given an expected average speed and known distance, figuring out how fast you'd need to travel to cover a distance within a deadline, or calculating the distance covered on a journey when you only know your speed and how long you traveled.