Speed, Distance & Time Calculator
Find speed, distance or time from the other two, in any units.
How to use this tool
- Enter any two of speed, distance and time.
- Choose units.
- The third value is computed — plus an ETA if you give a start time.
How it works
speed = d/t; distance = speed x t; time = d/speed. Mixed time units normalize to a single base before calculation.
Tips
- Average speed over a trip divides total distance by total moving time, not clock time.
- Add buffer for stops when budgeting journeys.
Limitations
Assumes constant speed; real traffic varies wildly.
Frequently asked questions
How is average speed found?
Speed = distance / time. Drive 150 miles in 2.5 hours and you average 60 mph.
Can it find arrival time?
Enter start time and travel duration to get the ETA.
Which units work?
Miles or kilometers for distance; hours, minutes or seconds for time.