Negative Split Calculator

Negative Split Calculator

The fastest way to run a distance is rarely an even pace — it is a slight negative split, holding back early and finishing strong. Enter the distance, your goal finish time and the negative split percentage you want, and this calculator returns your first-half and second-half pace per kilometre plus the exact time to pass halfway. Use it to plan a smart race and resist the urge to go out too hard.

A negative split means running the second half of a race faster than the first — the pacing strategy behind most distance running personal bests and world records. Enter your distance, goal time and how much faster you want the second half to be, and this gives the pace for each half and the time you should hit at halfway. A 1–3% negative split is realistic for most runners; start too fast and you fade instead.