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LunaCalc

Sports

Running Split Calculator

Plan running split pace and timing for training or races.

Calculator
Results
Additional running details

About this calculator

This splits calculator breaks a total race time into even per-kilometer or per-lap splits for pacing plans.

Formula notes

split time = total time / number of segments; cumulative time = split × segment number.

Worked examples

  1. Example: a 25:00 5K target means 5:00 per kilometer — 10:00 at 2 km, 15:00 at 3 km, 20:00 at 4 km.
  2. A 1:45:00 half-marathon target divided into 5 km segments gives checkpoints near 24:53, 49:46, 1:14:39, and 1:39:32 before the final 1.0975 km.

How to use it

  1. Enter the total distance and target time.
  2. Choose the split length, like each kilometer.
  3. Read the per-split and cumulative times.

Frequently asked questions

What are negative splits?

Running the second half faster than the first — often the most efficient race strategy.

Should track splits differ from road splits?

Track splits use 400 m laps; convert your per-km pace to per-lap by multiplying by 0.4.

Limits and interpretation

  • Even splits are a mathematical plan and may not be optimal for elevation, weather, crowding, aid stations, or individual pacing strategy.
  • Rounding each segment independently can make displayed split totals differ by a few seconds from the exact finish target.