Running pace calculator
Example result
5 kmBuild your race splits
| Split | Segment | Split time | Elapsed | Pace / km |
|---|---|---|---|---|
| 1 | 1 km | 5:00 | 5:00 | 5:00 |
| 2 | 1 km | 5:00 | 10:00 | 5:00 |
| 3 | 1 km | 5:00 | 15:00 | 5:00 |
| 4 | 1 km | 5:00 | 20:00 | 5:00 |
| 5 | 1 km | 5:00 | 25:00 | 5:00 |
Race times at the same pace
Constant pace, not a race prediction.
| Race | Finish time | Explore |
|---|---|---|
| 5K | 25:00 | Pace chart → |
| 10K | 50:00 | Pace chart → |
| Half marathon | 1:45:29 | Pace chart → |
| Marathon | 3:30:59 | Pace chart → |
More calculators
Track laps & repeat sessions
Uses the pace in the main calculator. Lap distance is nominal; outer lanes and restricted paths can be longer or incomplete. Check the venue timetable.
Run / walk finish calculator
Separate from the split plan; excluded from its shared link and CSV.
Estimate another race time
Use a recent endurance race in the main calculator. This distance-only model assumes comparable preparation and conditions. It is not a target you are guaranteed to sustain.
Default assumption: 1.06. A higher exponent applies more slowdown as distance increases. Sprint performances and very long events are poor inputs for this model.
Analyse an actual run
| Checkpoint | Segment | Split time | Elapsed | Pace / km |
|---|
Pace, speed & race-time chart
Pace questions
How do I calculate running pace?
Divide total time by distance. A 5 km run in 25 minutes is 25 ÷ 5 = 5 minutes per kilometre, or 5:00/km. To find finish time, multiply pace by distance. 5K pace chart →
What pace is a four-hour marathon?
A four-hour marathon over 42.195 km requires an average of about 5:41.3/km or 9:09.2/mile. The same pace completes a 21.0975 km half marathon in two hours. Split plans keep the unrounded pace. Marathon pace chart → Half marathon pace chart →
What is the difference between pace and speed?
Pace is time per kilometre or mile; a smaller value is faster. Speed is distance per hour; a larger value is faster. For example, 5:00/km equals 12 km/h and about 8:02.8/mile.
Should I enter moving time or elapsed time?
Use elapsed time when planning a race finish, including any stops you want to allow for. Moving time excludes stops. Choose the same definition when comparing runs.
How does a negative split work here?
The 51/49 option assigns 51% of total time to the first half of the distance and 49% to the second. It preserves your chosen finish time. It is a planning scenario, not a recommendation that this strategy suits every runner or course.
Why can a rounded pace differ from an exact finish target?
Many finish targets require a fractional-second pace. The tool keeps that precision internally. Repeatedly using a rounded pace on a watch can add or remove a few seconds over a long race.
Calculations, rounding & sources
Pace = time ÷ distance. Speed = distance ÷ time. One international mile is exactly 1,609.344 metres. A half marathon is 21.0975 km and a marathon is 42.195 km.
Calculations retain full precision. Displayed paces are rounded to a tenth of a second and finish clocks to the nearest second. Split durations are differences between rounded cumulative clocks, so their sum equals the displayed finish.
The race estimate uses T₂ = T₁ × (D₂ / D₁)ᵇ. The exponent is an editable assumption, initially 1.06. It does not model your training, weather, terrain or fuelling.
Your calculations and checkpoint text stay in this browser. Copying a plan creates a shareable URL fragment. No sign-in or activity upload is required.