Splits calculator.
Enter a race distance, finish time, and desired split interval to generate even splits, lap times, and cumulative checkpoints.
Plan your splits
Splits
| # | Checkpoint | Lap | Cumulative |
|---|---|---|---|
| — | — | — | — |
How split times are generated
The splits table is built from the same pace and speed relationships used in the pace calculator, with an additional step to chunk the race into equal intervals.
- Convert distance and interval to kilometres (1 mile = 1.60934 km) so the math works in a single unit system.
- Compute total seconds per kilometre (pace = time ÷ distance) and multiply by the interval size to get each lap time.
- Accumulate lap times to produce the cumulative column and re-convert checkpoints back into the user’s chosen units for display.
Even vs. varied pacing
| Approach | Pluses | Minuses |
|---|---|---|
| Even splits (default) | Simple to memorise, keeps effort steady, aligns with most record attempts. | Doesn’t model terrain or tactical surges; you must adjust manually for hills or turns. |
| Negative split (manually adjust) | Can reflect championship racing strategy and fatigue management. | Requires editing the exported CSV or manually tweaking laps—this tool doesn’t currently automate it. |
Because checkpoints are derived from evenly spaced intervals, rounding is applied only in the final display (to the nearest second). Exported CSV values retain millisecond precision so you can customise them in a spreadsheet if you need bespoke pacing plans.
Integrating splits with your training
Once you generate a pacing table, incorporate the numbers into key workouts so race day feels familiar.
- Track sessions: convert kilometre splits into 400 m lap targets and practice hitting them during VO₂ max intervals.
- Long runs: insert goal pace segments that match the split interval (e.g., 3 × 5 km at marathon pace) to rehearse fueling and check how pace drifts.
- Tempo workouts: use the per-mile output to fine-tune threshold runs and confirm your watch calibration.
Review how closely you stick to the plan during training; large deviations may indicate the need to adjust your target finish time.
Example use cases
Here are scenarios where the splits calculator adds clarity:
- Marathon pace bands: generate 1-mile splits, export to CSV, and laminate or tape to your bottle or wrist.
- Track meets: coaches can pre-print lap sheets for athletes in the same heat, ensuring call-outs stay accurate.
- Negative split experiments: export the plan, then edit the final third to be 2–3 seconds faster per split to practice late-race surges.
- Virtual races: use the table to program treadmill workouts with precise pace segments.
Annotate the plan with aid station locations, course turns, and mental cues so the pacing sheet becomes a complete race guide.
Splits calculator FAQs
Expand the accordions to learn how to customise or troubleshoot your pacing plan.
Can I plan negative or positive splits?
The calculator defaults to even pacing. Export the CSV and adjust later splits up or down to reflect negative or positive strategies.
How do I factor in hills or wind?
Overlay course elevation on your split plan and add time to uphill segments while subtracting on descents. Consider effort targets rather than exact seconds in extreme conditions.
What intervals should I choose?
Use 1 km or 1 mile for road races, 400 m for track, and aid-station spacing (e.g., every 5 km) for marathons so checkpoints align with logistics.
Why does my pace look off compared to GPS?
GPS courses often measure long; aim to run tangents and expect a slight pace discrepancy. Use elapsed time at official markers to stay on plan.
Can I share the plan with teammates?
Yes—download the CSV and send it to training partners or import into Google Sheets to collaborate on adjustments.