Running Pace Calc

Key features

• Three solving modes: find your pace from time and distance, project a finish time, or work out how far you'd get.
• Race presets: 5K, 10K, half marathon (21.0975 km), marathon (42.195 km) and 400 m.
• Distances in kilometres, miles or meters — with pace and speed always returned in both metric (min/km, km/h) and imperial (min/mi, mph).
• An even-pace split table with one row per kilometre or mile, including a partial final split when the distance isn't whole.
• Splits capped at 100 rows for very long efforts, with a note explaining exactly what's shown.

How it works

1. 1

   Pick what to solve

   Tabs switch between Pace, Time and Distance; the fields you don't need disappear.

2. 2

   Enter the known values

   Distance with its unit, a finish time as h/m/s, or a pace as minutes and seconds per km/mi.

3. 3

   Read the headline stats

   Pace per km or mile, speed in km/h, and the value you solved for.

4. 4

   Study the splits

   In pace mode, a table lists even-effort splits with cumulative clock times — your pacing cheat sheet.

5. 5

   Cross-check units

   The info line always shows pace per km AND per mile, plus speed in km/h AND mph.

Tips for better results

• 💡Marathon preset + a 3:30:00 finish works out to about 4:59/km (8:01/mi) — then follow the split table through the halfway point.
• 💡Splits assume even effort; hills, heat and fatigue make real races negative or positive splits. Treat the table as a target, not a promise.
• 💡For track workouts, use the 400 m preset with meters — the tool converts internally and keeps pace per km.
• 💡The half marathon is 21.0975 km — entering 21 underestimates your time by roughly 29 seconds at 5:00/km pace.

Frequently asked questions