The formula
How it works
Pace is how long it takes you to cover one kilometre or mile. Enter a distance and the time it took, and the calculator returns your pace and your average speed — the two numbers runners use to plan and compare runs.
FAQ
What’s the difference between pace and speed?
Pace is time per distance (like 5:00 per km), while speed is distance per time (like 12 km/h). They describe the same run — a faster pace means a lower number, but a higher speed.
How do I use pace to predict a race time?
Multiply your target pace by the race distance. A 5:00/km pace over 10 km is 50 minutes. Keep in mind most runners slow slightly over longer distances.
How do I convert pace between km and miles?
Multiply a per-km pace by 1.60934 to get a per-mile pace, or divide a per-mile pace by 1.60934 to get a per-km pace. A 5:00/km pace works out to roughly 8:03/mi.
What is a negative split?
Running the second half of a race faster than the first. Many coaches recommend it, or at least an even pace, since starting too fast at a quicker-than-sustainable pace often costs more time later than it gains early on.
Does incline change my effective pace?
Yes — running uphill at the same effort produces a slower pace, and downhill a faster one, even though your effort level may be similar. Treadmill and GPS paces on hilly routes should be compared with that in mind.
How do training paces relate to race pace?
Easy runs are typically 60–90 seconds per km slower than race pace, while interval or tempo paces are faster than it. Plans often express workouts as a percentage or offset of your goal race pace rather than an absolute speed.
Why does my GPS watch pace fluctuate?
GPS signal noise, tree cover, and tall buildings can make instantaneous pace readings jump around even when your actual effort is steady. Average pace over a longer stretch, like this calculator computes, is more reliable than the moment-to-moment number.
About the pace calculator
This calculator turns a distance and a time into a running pace and an average speed. Pace — the minutes and seconds it takes to run one kilometre or mile — is the language runners use, because it is easy to hold in your head and to aim for on a watch. Whether you are training for a 5K or pacing a marathon, knowing your pace helps you run evenly and hit the finish time you want.
How to use it
Choose kilometres or miles, enter the distance you ran, then type the time as hours, minutes and seconds. The calculator shows your pace per kilometre or mile, and your average speed. For example, running 10 km in 50 minutes is a pace of 5:00 per km and a speed of 12 km/h. Change the distance unit to switch between metric and imperial, and adjust the time to see how a faster effort changes your pace.
The formula
Pace is simply the total time divided by the distance, . To get a clean minutes-and-seconds figure, the time is first converted entirely into seconds, divided by the distance, then converted back. Average speed is the reverse ratio, , usually expressed per hour. Because pace and speed are reciprocals, a pace of 5 minutes per km is the same as 12 km per hour.
Where it is used
Runners rely on pace for everything from easy training runs to race-day strategy, where going out too fast is the classic mistake. Coaches prescribe workouts in pace terms — intervals at a set pace per km, for instance. Cyclists, swimmers and walkers use the same idea with their own units. Race organisers use pace to set finishing-time cut-offs and to seed runners into starting waves, and pace charts help spectators know when a runner will pass.