Enter any two of the three values: time, distance and pace. The calculator solves the third one instantly. Pick a preset distance (5K, 10K, half marathon or marathon) or type your own distance in kilometers or miles, then add either a target time or a target pace.
One mile is 1.609344 kilometers, so multiply your per-km pace by 1.609344. For example, 5:00 per km is 300 seconds per km, times 1.609344 gives about 483 seconds, so about 8:03 per mile. The calculator does this automatically when you switch units.
The marathon is 42.195 km (26.2 miles), so the math is fixed: a 3:00 marathon needs about 4:16 per km (6:52 per mile), 3:30 needs about 4:59 per km (8:01 per mile), 4:00 needs about 5:41 per km (9:09 per mile), and 4:30 needs about 6:24 per km (10:18 per mile).
Splits assume perfectly even pacing: the cumulative time at each whole kilometer (or mile, if you use miles) is that distance multiplied by your pace, with a final row at the exact race distance. Real races rarely go perfectly even, so treat them as a pacing reference, not a prediction.
Pair this calculator with two other Marathon Ballot tools. The race time predictor estimates your marathon or half time from a recent shorter race, so you can check your goal against current fitness. The qualification checker then tells you what that finish time means across all eight Abbott World Marathon Majors: qualified, close, or ballot.