Race Split Planner
Generate a mile-by-mile or km-by-km split plan for any race distance and goal time. Even splits or negative splits — print and take it to the start line.
| Split | Split Time | Cumulative Time |
|---|
What Is a Split Plan?
A split plan tells you exactly how fast to run each mile (or kilometer) of your race to hit your goal finish time. Following a split plan prevents the most common race mistake: going out too fast and struggling to the finish.
Even Splits vs. Negative Splits
Even splits means running every mile at the same pace — the most energy-efficient way to race a given time. It’s the right choice for most runners in most races.
Negative splits means running the second half faster than the first. A 1–2% negative split is considered optimal for marathon performance. The idea is to bank effort (not time) by starting slightly conservative, then accelerating when others are fading.
How to Use the Split Planner
- Select your race distance and enter your goal finish time.
- Choose your pacing strategy (even or negative split).
- For a negative split, set the second-half advantage (0.5–5.0%) — start with 1%.
- Print or save the table as a PDF to carry on race day.
A Note on Negative Split Percentages
The percentage refers to how much faster your second half will be relative to your first half. A 2% negative split for a 3:00:00 marathon means your first half takes roughly 1:30:54 and your second half 1:29:06.