Pace Calculator
Calculate running pace, finish time, or distance — solve for any one from the other two — plus speed and predicted 5K, 10K, half, and marathon finish times.
Pace is the number every runner lives by. This calculator is a three-way solver — enter any two of pace, time, and distance and it works out the third, then shows your speed and predicted finish times for standard race distances.
The three modes
Pick what you want to solve for:
- Pace — enter distance + time to get your pace (the classic use).
- Time — enter distance + a target pace to get your finish time.
- Distance — enter a pace + a time to get how far you’d cover.
How pace is calculated
Pace is simply time divided by distance:
pace = finish time ÷ distance
Run 10 km in 50:00 and your pace is 5:00 per km. Converted to imperial that’s about 8:03 per mile, or a speed of 12.0 km/h (7.46 mph). The calculator handles all four representations at once, and lets you enter distance in either kilometres or miles.
Predicted race times
Using your current pace, the calculator projects finish times for the classic race distances:
| Race | Distance |
|---|---|
| 5K | 5 km |
| 10K | 10 km |
| Half marathon | 21.0975 km |
| Marathon | 42.195 km |
These assume you hold the same pace throughout. That’s realistic over similar distances, but for big jumps — say projecting a marathon from a 5K — expect to be a little slower in reality, because pace naturally drifts over longer efforts (a pattern captured by Riegel’s classic race-prediction model).
Using pace in training
Plan even splits by picking a goal finish time and reading off the pace you need to hold. On race day, starting at or just slower than that pace and speeding up in the second half (“negative splits”) is a reliable way to run a strong time.
Frequently asked questions
How is running pace calculated?
Pace is your finish time divided by the distance. Run 10 km in 50 minutes and your pace is 50 ÷ 10 = 5:00 per kilometre. This calculator also converts that to pace per mile and to speed in km/h and mph.
What's the difference between pace and speed?
They describe the same thing from opposite directions. Pace is time per distance (minutes per km/mile) and gets larger as you slow down; speed is distance per time (km/h or mph) and gets larger as you speed up. Runners usually think in pace; treadmills usually show speed.
How does it predict my race times?
The predicted finish times assume you hold the same pace for the whole distance. That's a good guide for short jumps in distance, but for much longer races most runners slow down slightly, so a full marathon at your 5K pace will usually be optimistic.
What's a good running pace?
It's completely individual and depends on fitness, distance, and terrain. Rather than chasing an absolute number, use the calculator to track your own paces over time and to plan even splits for a target race.