Pace Calculator
Give it any two of distance, time and pace. The board answers with the third while you type.
Race Distances and the Pace Formula
Pace is time divided by distance. Lock in any two of the three and the last one has nowhere to hide, which is all this calculator does, over and over, on every keystroke. The highlighted field is the one being solved; edit any other field and the solver switches to whichever value you touched least recently.
Common race distances
| Race | Kilometres | Miles |
|---|---|---|
| 5K | 5 | 3.11 |
| 10K | 10 | 6.21 |
| Half marathon | 21.0975 | 13.11 |
| Marathon | 42.195 | 26.22 |
Worked example
Chasing a sub 50 minute 10K? That's 50 minutes over 10 km, so 5:00 per kilometre, no slower. Flip it around for race day planning: hold 5:00 per km over a full marathon and you'll cross at 3:30:59.
The unit toggle converts everything in place. One mile is 1.609344 km, so a 5:00 min/km pace becomes 8:03 min/mile, same speed, different label. Preset buttons drop in the official race distance using whichever unit is active.