Running Pace Calculator
Calculate running pace, finish time, distance, and mile/km splits for any race. Your work stays on this device whenever possible.
How to use Running Pace Calculator
- Open 'I Want to Calculate' and choose pace, time, distance or 'Race Time Predictor (from 5K/10K Time)'.
- Pick an 'Event / Distance Preset' such as 5K, Half Marathon or Marathon, or choose 'Custom Distance' and enter a value in km or miles.
- Enter the 'Finish Time (Hours : Minutes : Seconds)', or the 'Pace (Minutes : Seconds per Unit)' with per Mile or per KM selected.
- For predictions, set 'Known Race' to 5K or 10K and fill 'Known Time (hh:mm:ss)'.
- Press 'Calculate' and read the paces, speeds and split tables; 'Load 5K Sample' and 'Reset Marathon' restore demo values.
Worked example
Choose 'Pace', the 5K preset and a finish time of 0:25:00. That is 1500 seconds over 5 km, so the pace is 300 s = 5:00 per km. Per mile it is 1500 ÷ 3.10686 ≈ 483 s = 8:03, with speeds of 12.00 km/h and 7.46 mph. In predictor mode, a 5K of 24:30 gives 51:05 for 10K.
When to use this tool
- Planning even splits for a goal half marathon and checking the mile times against a wristwatch.
- Converting a treadmill display in minutes per mile into minutes per kilometer.
Important limitations
Calculates even splits across flat terrain and does not model elevation changes, fatigue curve degradation, or weather variables. Input times must use positive non-zero hours, minutes, and seconds.
Comparing alternatives
Other options for running pace calculator include Runner’s World, Active.com, MarathonGuide.
ToolkitPoint is not affiliated with those services.
Frequently asked questions
What formula does the predictor use?
Riegel's endurance rule, T2 = T1 × (D2 ÷ D1)^1.06, applied to a known 5K or 10K time. It outputs the 10K, half marathon and marathon, and assumes training that suits the longer distance.
How many splits are listed?
Up to 30 mile rows and 45 kilometer rows, so a 50K event stops before its final splits. The last row of shorter events is labeled 'Finish' with the exact distance.
Does distance mode use the preset?
No. It divides your entered time by the pace and reports the answer in both miles and kilometers, so the preset menu plays no part there. Fifty minutes at 5:00 per km comes out at 10.00 km.
How is rounding handled?
Times and paces are rounded to whole seconds when displayed, so the per-mile and per-kilometer figures for the same effort can differ by a second.
Which marathon length is used?
Pace and time modes use 42.194988 km for the marathon preset, while the predictor uses 42.195 km. The difference is far below one second per mile, so it will not visibly change any split or finish time.