Tools you might need next
Estimate VO2 max from race times, Cooper 12-minute test, or resting heart rate. Measure aerobic fitness for running and cycling training.
Calculate heart rate training zones from max HR, lactate threshold, or Karvonen formula. Set easy, tempo, threshold, and interval zones for running.
Calculate even, negative, or progressive split times for race distances. Plan mile or kilometer checkpoints for marathon and half marathon pacing.
Divide total time by distance to get pace per unit. For a 45-minute 10K: 45/10 = 4:30 per km.
Pace (min/km) = Total time (min) / Distance (km)Multiply pace by distance for projected finish time. Convert pace minutes and seconds to decimal minutes first.
Finish time = Pace (min/unit) × DistancePace and speed are reciprocals. Speed in km/h = 60 / pace in min/km. Speed in mph = 60 / pace in min/mile.
Speed (km/h) = 60 / Pace (min/km)Updated: July 2026
Marathon 26.2 miles in 4:00:00 requires 9:09 per mile pace. Halfway split target: 1:59:30 at mile 13.1 for even pacing with slight negative split margin.
5K in 25:00 = 5:00 per km or 8:03 per mile. Kilometer splits: 5:00, 10:00, 15:00, 20:00, finish 25:00.
Half marathon 21.1 km in 1:45:00 = 4:58/km pace. 5K checkpoints at ~23:30, 10K at ~47:00, 15K at ~1:10:30.
The first mile should feel slightly easy — 5–10 seconds per mile slower than goal pace. Starting at goal pace from the gun causes early lactate accumulation and late-race fade.
Easy run pace is 60–90 seconds per mile slower than race pace for most runners. Base race pace on recent time trials, tempo runs, or equivalent race results.
Hitting a target finish time requires knowing your required pace per mile or kilometer and intermediate split checkpoints. This calculator converts between pace, speed, distance, and total time for any race distance so you can plan even or negative splits.