Split Calculator

Choose a distance, target time or pace, and the distance between splits. For example, 10K in 40:00 with 1 km splits. With Even Pace, every kilometre is 4:00. With a Moderate Negative Split of 4%, you start at about 4:05/km and finish at about 3:55/km. You can edit each split’s pace individually. The total time updates automatically, showing the difference from your target.

This calculator performs a mathematical calculation, not a race prediction. Gradients, wind, heat and aid stations often require adjustments on race day. For these conditions, see GAP, the Wind Pace Calculator and the Heat Pace Calculator. If the distance does not divide evenly, the final split covers the remainder: for example, marathon splits every 5 km leave a final split of 2.195 km.

Even Pace: the same pace in every segment. Negative Split: a linear change from split to split. With Moderate Progression at 4%, the first split starts about 2% slower and the last finishes about 2% faster than the average pace. The 4% describes the total change from first to last split, not the difference between the first and second halves. Normalisation: times are scaled at the end so their sum exactly matches the target time. Display is rounded to the nearest second.

Last updated: 20 June 2026