What this result means
This table always splits every kilometre. Distance and time are yours; the interval is not. That is the difference from the general race split calculator, which follows the km/mi header or a 5 km option.
Use it when a race or a loop is marked in kilometres and you want every marker, including a 15 km, a 25 km, or a 30 km training run.
A 21.1 km goal in 1:45:00 is 4:59 per kilometre even. 5 km is 24:53, 10 km is 49:46, 20 km is 1:39:32, finish 1:45:00. A 10 km in 50:00 is 5:00, 10:00, 15:00 through 10 km.
A 30 km in 2:15:00 is 4:30/km. Halfway (15 km) is 1:07:30 on even splits. The last row is always the finish, even when the distance is not a whole number of kilometres.
Calculation method
Each kilometre time is target time multiplied by (kilometre index ÷ distance). The finish row uses the full time. Displayed times round to the nearest second.
Exact arithmetic. The unit toggle still converts the distance you type; it does not change the 1 km interval.
Even kilometres ignore a faster close. For mile markers use the mile split calculator. For a faster second half use negative splits.
Frequently asked questions
Why not use the race split calculator?
You can. This page locks 1 km so a mile-unit header cannot change the interval. It is the kilometre-only landing.
What are even 1 km splits for 1:45:00 at 21.1 km?
4:59 per kilometre. 10 km at 49:46, 20 km at 1:39:32, finish 1:45:00.
Does it work if the distance is 21.0975 km?
Yes. Whole-kilometre rows stop before the finish; the last row is the true finish time.
Should I use the half-marathon pace calculator instead?
Use that page when the distance is the official half and you want average pace plus a short split list. This page is every 1 km row for any distance.