Speed, Distance and Time Calculator
Speed, distance or time from the other two, the true average speed over several legs of a journey, and the time a faster speed really saves.
Result
Time: 04:00:00
Assumes a steady speed. Real journeys include stops and slow stretches.
- Speed
- 60 mph
- Distance
- 240 mi
- Average speed over the legs
- 40 mph
- Mean of the leg speeds, which is not the average
- 45 mph
https://calcgallery.com/vehicle-specs/speed-distance-time-calculator/
Results are arithmetic on the figures you enter. The site stores no vehicle data, fuel prices, mileage rates, depreciation rates or residual values, because they vary by model and place and change over time. Real fuel economy varies with driving, weather and load. Nothing here is a fitment, safety or financial recommendation. Read the full disclaimer
How to use the Speed, Distance and Time Calculator
- Choose whether to find the time, the speed or the distance, and enter the other two.
- Optionally enter another speed to see how much time it would save or cost.
- For a journey in stages, list each leg's distance and speed to see the true average speed.
The formulas
speed = distance ÷ timedistance = speed × timetime = distance ÷ speedaverage over legs = total distance ÷ total timeSolving for any one of the three from the other two and back returns the same values; units are converted exactly on the way in and out.
The average-speed trap
Averaging speeds directly only works when each speed lasted the same time. When each lasted the same distance, as on the way there and back, the right average is the harmonic mean, and it is always lower than the plain mean unless the speeds are equal. The same arithmetic makes dollar-cost averaging buy at an average cost below the average price.
With your numbers
- 240 mi at 60 mph takes 4 hours
Quick reference
Assumes a steady speed. Real journeys include stops and slow stretches.
| Example | Result |
|---|---|
| 240 mi at 60 mph | Time: 04:00:00 |
| 400 km in 4:30 | Speed: 88.89 km/h |
| 65 mph for 2:45 | Distance: 178.75 mi |
| 100 mi at 70, against 80 mph | Time: 01:25:43 |
| 100 mi at 30, against 40 mph | Time: 03:20:00 |
| 60 mi at 30 then 60 at 60 | Time: 03:00:00 |
Common questions about the Speed, Distance and Time Calculator
- Why is the average speed not the average of the speeds?
- Because you spend longer at the slower speeds. Drive 60 miles at 30 mph and 60 miles at 60 mph: that is 120 miles in 3 hours, an average of 40 mph, not 45. The true average is total distance over total time, which weights each speed by how long you spent at it. The legs section shows both.
- How much time does driving faster save?
- Less than it feels, and less the faster you already go. Over 100 miles, going from 70 to 80 mph saves about 10 minutes 43 seconds; going from 30 to 40 mph saves 50 minutes. The saving shrinks as speed rises because time is distance divided by speed.
- How do I enter the time?
- As hours, minutes and seconds, such as 4:30:00 for four and a half hours. The answer for time is shown the same way.
- Can I use knots or metres per second?
- Yes, the speed field accepts mph, km/h, m/s and knots, and converts them exactly.