Running Split Calculator
Build even kilometer or mile splits for a 5K, 10K, half, marathon, or custom distance.
Splits are the clock time at each marker if you run the same pace the whole way. Enter a distance and a finish time. The table shows the time for each segment and the time you should see when you pass that marker.
Calculator Inputs
Used only when distance is set to custom.
Results
Enter values above to see your results
How to use this calculator
- Choose a race or “custom distance.” The example is a 10K in 55:00 with a split every kilometer.
- Change “split every” to 1 mile or 5 kilometers when those markers are what the course uses. Mile splits on a kilometer course still work; the last row is the leftover distance.
- Write the cumulative column on a wristband if you want checkpoint targets. The split column is only the time since the previous marker.
How the calculation works
Even pace means each slice of the race takes the same fraction of the finish time. Split time = finish time × (interval ÷ total distance). Cumulative time = finish time × (marker ÷ total distance).
For a 10K in 55:00, the total is 3,300 seconds and each kilometer is one tenth: 330 seconds, or 5:30. The cumulative time at 6 km is 6 × 5:30 = 33:00.
Mile markers use a 1.609344 km interval. On a 10K that produces six full miles and a short finish remainder because 10 km is 6.214 miles. The remainder split is shorter than the mile rows above it.
When even splits are the wrong target
The table is a ruler, not a pacing strategy. A hilly course, a crowded start, or a plan that starts slightly slower will not match these rows. If you run the first mile 20 seconds fast, every later cumulative time in the table is already behind you.
Use kilometer splits for 5K and 10K racing. Use 5K splits for the half and the marathon unless you specifically need mile marks. A 42-row kilometer table is harder to read on a watch than eight 5K checkpoints.
Worked example
10K in 55:00, every kilometer
55 × 60= 3,300 s3,300 ÷ 10= 5:305:30 × 5= 27:305:30 × 10= 55:00Frequently Asked Questions
What is a split in running?
A split is the time for one section of a run, and the cumulative split is the time from the start to that marker. This calculator prints both for an even pace.
How do I get negative splits?
Run the first half slightly slower than the average pace in the table, then faster than average after halfway. The cumulative time can still match the finish row if the two halves balance.
Why is the last split shorter?
The interval does not always divide the race evenly. A marathon split every 5 km has 2.195 km left after 40 km. A mile-split 10K has 0.214 miles left after 6 miles.
Guides & Articles
Average Half Marathon Times by Age
A half marathon is 21.0975 km. Wide planning ranges by age, the pace at each end, and why a published average is a weak target.
Average Marathon Times by Age
Marathon planning ranges by age, with the pace at each end. These are coaching bands, not race medians. A 4:00 marathon is 5:41 per kilometer at every age.
How Long Does a 10K Take?
10K pace chart from 40:00 to 1:10:00. A 10K is 10 kilometers, or 6.214 miles, with the halfway split at even pace.
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