That depends on what data you have. If you know the distance travelled and the time it took, just divide the total distance by the total time. If distance is in kilometers, and time in hours, then the speed will quite naturally come out in km/hour.
Chat with our AI personalities
Average speed = Total distance/Total time
9km per hour
Her average speed was 58 miles per hour.
The average speed is 110 km per hour.
The train's average speed was 34.5 miles per hour.