Conversion Calculators
Speed Calculator
Enter a distance and elapsed time to calculate average speed. Choose metres, kilometres, miles or feet; seconds, minutes or hours; and m/s, km/h, mph or knots. Distance must be non-negative and time positive. The result is the average over the interval, not instantaneous speed or a route estimate.
Calculator
Formula used
Distance ÷ elapsed time; convert the inputs to metres and seconds before dividing.
About This Calculator
What It Does
This calculator derives average speed from a distance and elapsed time. It converts the selected distance and time to metres and seconds, divides distance by time, then converts the result into the selected speed unit. The supported distance units are metres, kilometres, miles and feet; time units are seconds, minutes and hours; speed units are metres per second, kilometres per hour, miles per hour and knots.
Worked Example
With the defaults, 100 kilometres ÷ 2 hours = 50 kilometres per hour. The same journey is 100,000 metres ÷ 7,200 seconds = 13.8889 metres per second, approximately. A second example is 60 miles ÷ 1 hour = 60 miles per hour. Choosing another output unit changes the presentation, not the underlying speed.
Real-World Usage
Use the calculator to estimate average travel speed from a known journey length and duration, compare pace across units, or convert a trip record into a speed commonly used in a vehicle or marine context. It can also help check classroom distance-rate-time problems. Enter only the total distance and elapsed time for the interval being assessed.
Local Context
The calculation treats the distance as travelled along the measured path and the elapsed time as the complete interval. It does not infer a route, subtract breaks, model acceleration or stops, or report instantaneous speed. Zero distance is valid and gives zero speed; elapsed time must be positive. Unit conversions use exact international definitions for miles, feet and nautical miles; displayed decimals are rounded for readability.
Last reviewed: October 2026.
Frequently Asked Questions
How is average speed calculated?
Average speed is total distance divided by total elapsed time, after both inputs are converted to standard units.
Which units are supported?
Distance: metres, kilometres, miles and feet. Time: seconds, minutes and hours. Speed: metres per second, kilometres per hour, miles per hour and knots.
Does this show instantaneous speed?
No. It computes the average across the whole interval. It does not account for stops, changes in speed, route conditions or acceleration.