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RUNNERS LAB

Positive Split
Calculator

Build a checkpoint table where the second half is slower than the first.

Last reviewed 19 August 2026

A positive split means the second half is slower than the first. With a 2% fade, the first half is quicker and the close is slower, still adding to the goal time. Many road races play out this way even when the plan was even. This table makes that fade explicit.

KM
Target time

Enter the finish time you want to run.

%

Typical race plans use 1–3%.

Positive-split finish

1:45:00

  • First km 4:56
  • Last split 5:02

Your splits

Checkpoint times with a faster or slower second half
MarkerSplitPaceTime
1 KM4:564:564:56
2 KM4:564:569:51
3 KM4:564:5614:47
4 KM4:564:5619:42
5 KM4:564:5624:38
6 KM4:564:5629:34
7 KM4:564:5634:29
8 KM4:564:5639:25
9 KM4:564:5644:21
10 KM4:564:5649:16
11 KM4:584:5854:15
12 KM5:025:0259:16
13 KM5:025:021:04:18
14 KM5:025:021:09:19
15 KM5:025:021:14:21
16 KM5:025:021:19:22
17 KM5:025:021:24:24
18 KM5:025:021:29:25
19 KM5:025:021:34:27
20 KM5:025:021:39:28
21 KM5:025:021:44:30
Finish0:305:021:45:00

What this result means

Positive splitting is the opposite of a negative split: the first half is faster, the second half slower. Sometimes that is the plan — a packed first 5K, a hilly second half, or an honest forecast of fade. This calculator writes the checkpoints.

It shares the same engine as the negative-split tool with the sign flipped. Even splits remain on the race split calculator. Use this page when you want the fade on paper instead of pretending you will hold even.

A 1:45:00 half with a 2% positive split spends less than half the time on the first 10.55 km and more on the close. Early kilometres are quicker than the last ones. The finish is still 1:45:00.

A 4-hour marathon with a 3% positive split goes through halfway faster than 2:00:00 and pays it back after 30 km. That can be realistic on a hot day. It is also how people blow up if the first half is too fast.

Calculation method

The drop is negative of the fade percent. First-half time is total ÷ (2 − drop). Because drop is negative, the first half is shorter in time (faster). Second-half pace is slower. Checkpoints switch pace at halfway.

Exact arithmetic. No glycogen model, no hill profile.

A planned positive split is not an excuse to sprint the first 5K. The table still has to add to the goal. If you cannot live with the late paces, lower the fade or pick a slower finish.

Full methodology →

Frequently asked questions

What is a positive split?

A slower second half than the first. This tool builds that table for a target time.

Why plan a positive split?

Hills after halfway, heat, or an honest fade forecast. It is also how many unplanned races look; writing it down can keep the first half from being worse.

Can I use this for a marathon?

Yes. Enter 42.2 km or switch units to miles and enter 26.2. For official marathon distance plus km and mile columns, use the marathon pace band.

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