Negative split calculator
A negative split means the second half is faster. These examples keep the total time fixed and shift seconds from the second half to the first.
Formula: first half = total / 2 + offset; second half = total / 2 - offset
Example: For a 50:00 10K with a 30-second negative split, halves are 25:15 and 24:45.
Reference table
| Input | Result | Also |
|---|---|---|
| 10K 50:00, 30 sec negative | 25:15 | 24:45 |
| Half 2:00:00, 60 sec negative | 1:00:30 | 59:30 |
| Marathon 4:00:00, 2 min negative | 2:01:00 | 1:59:00 |
FAQ
What is a negative split?
It means finishing the second half faster than the first half.
Does this prescribe effort?
No. It is only time arithmetic; course profile, heat and fatigue decide whether the plan is sensible.