What is a speed, distance and time calculator?
A speed, distance and time calculator solves one travel value when you know the other two. It is useful for planning journeys, checking a running or cycling pace, estimating delivery travel time, comparing routes and solving school maths problems. Select the value you need, enter the two known values and the result appears immediately.
The calculator supports metric units in kilometres and kilometres per hour, or imperial units in miles and miles per hour. It runs entirely in your browser, so the figures you enter stay on your device. Choose one unit system and keep the distance, speed and time values consistent within that system.
How to use the calculator
- Choose whether to calculate speed, distance or time.
- Select Metric for kilometres and km/h, or Imperial for miles and mph.
- Enter the two values you already know.
- Read the calculated result and its formula.
For example, a trip covering 120 kilometres in 2 hours has an average speed of 60 km/h. At a steady 60 km/h for 2 hours, the distance is 120 km. Covering 120 km at 60 km/h takes 2 hours. These examples use the same relationship viewed from three different directions.
The speed, distance and time formulas
Speed equals distance divided by time. Use this when you know how far a journey went and how long it took. Distance equals speed multiplied by time. Use it to estimate how far you can travel at a chosen average speed over a set duration. Time equals distance divided by speed, which is useful for an initial journey-time estimate.
The calculator expresses time in hours. You can enter a decimal when needed: 1.5 hours means 1 hour and 30 minutes, while 0.25 hours means 15 minutes. For a result in minutes, multiply the decimal hours by 60. Keep this conversion in mind when comparing a result with an itinerary that lists hours and minutes separately.
Why real travel can differ
This calculation assumes the speed is an average maintained throughout the journey. In real travel, traffic, waiting, rest breaks, hills, weather, junctions, speed limits and route changes can all make the final time longer. Use a realistic average speed instead of a maximum displayed speed, and add an allowance when a schedule matters. The result is a clear mathematical estimate, not a live traffic prediction.