Use the Split Calculator in five steps
Choose a race distance, target finish time, and split interval. The calculator then creates an even-paced schedule with individual split times and cumulative times.
Open the Running Split Calculator
Select the Running Split Calculator from the calculator library, or use the blue button at the top of this tutorial.
Choose your race distance
Select 5K, 10K, Half Marathon, Marathon, or Custom distance. For a custom distance, enter a value from 0.1 to 100 kilometres.
Enter your target finishing time
Fill in Hours, Minutes, and Seconds. For a 25-minute 5K, enter 0 hours, 25 minutes, and 0 seconds.
Choose a split interval
Select Every 0.5 km, Every 1 km, or Every 5 km. Your choice controls the distances between table rows.
Calculate and read the table
Select Calculate My Splits. Check the average pace, speed, number of splits, and table of interval and cumulative times. The last row is the planned finish.
These are target splits, not a record of a completed run. A uniform target pace may be adjusted on the day for terrain and conditions.
A 25-minute 5K with one-kilometre splits
Enter a 5K, a target time of 0:25:00, and a split interval of 1 km. Your pace is 25 ÷ 5 = five minutes per kilometre.
The resulting schedule looks like this:
| Split | Distance | Split time | Elapsed time |
|---|---|---|---|
| 1 | 0–1 km | 5:00 | 5:00 |
| 2 | 1–2 km | 5:00 | 10:00 |
| 3 | 2–3 km | 5:00 | 15:00 |
| 4 | 3–4 km | 5:00 | 20:00 |
| 5 | 4–5 km | 5:00 | 25:00 |
Each split time is the duration of one kilometre. Each elapsed time is the total time from the start to that marker.
Understand every result
Average pace per kilometre
The time needed for one kilometre at your planned even pace. A smaller number means a faster pace.
Average pace per mile
The equivalent pace expressed as minutes per mile. The calculator uses 1 mile = 1.609344 km.
Average speed in km/h
How many kilometres you would cover in an hour if you maintained the target pace.
Split time
The duration of the specific segment shown in a table row.
Elapsed time
The total time from the race start to the end of that segment. The last elapsed time is your chosen target finish.
How the split calculation works
The calculator converts your target time into seconds and divides it by the full race distance to find the even pace.
To find the ideal elapsed time at a distance marker, multiply the total target time by the fraction of the race completed.
The split time is the difference between successive elapsed-time markers. The calculator rounds each displayed marker to the nearest second and subtracts those rounded markers. This makes the displayed split times add up to your selected finish time.
Some adjacent split times may therefore differ by one second even though the calculated underlying speed is constant.
Half-marathon, marathon, and partial final splits
A half marathon is 21.0975 km, so its last segment with one-kilometre splits is only 0.0975 km, not a full kilometre. A marathon similarly finishes after 42.195 km.
The calculator automatically shortens the last interval instead of adding a complete kilometre. For example, a half marathon at 1-km intervals produces 22 rows: 21 full kilometre splits followed by a short final segment.
A 5-km interval gives a shorter overview; a 0.5-km interval offers more frequent checkpoints. For a short custom race distance, the final segment may be smaller than the selected interval.
Another example: 10K in 50 minutes
Choose 10K, enter 50:00, and select Every 5 km. The result has two segments, each taking 25:00, with cumulative times of 25:00 and 50:00.
Tips for using race splits
- Choose a realistic finishing time. Your target pace should reflect your preparation and event distance.
- Pay attention to cumulative times. They are useful at official race markers and aid stations.
- Remember course markers may differ. GPS distance and official race distance can be slightly different.
- Do not chase every second. The tool rounds to whole seconds; weather, hills, and crowds can affect individual splits.
- Use splits as a guide. Even pacing is only one possible strategy, not a prediction of what will happen.
Running Split Calculator FAQs
What is the difference between split time and elapsed time?
Split time is the duration of one segment; elapsed time is the total from the start through that segment.
Can I use a custom distance?
Yes. Select Custom distance and enter a value from 0.1 to 100 kilometres.
What interval lengths are available?
You can choose 0.5 km, 1 km, or 5 km. The final segment is shortened automatically if needed.
Why do two equal-distance splits sometimes differ by one second?
Each checkpoint is rounded to whole seconds. Subtracting those rounded checkpoints preserves your exact target time.
Can I calculate half-marathon or marathon splits?
Yes. Select the race from the distance menu; the calculator uses 21.0975 km or 42.195 km and handles partial final intervals.
Does the table show negative splits?
No. The calculator creates an even-pace plan. Negative splits require a progressively faster pace during the second part of a race.