Pace Calculator — Running Pace, Time & Distance
Distance
Time (h : m : s)
Pace (min : sec per unit)
—
min/km
—
min/mile
—
total time
—
distance
—
km/h
—
mph
Split chart
| Distance (km) | Cumulative time |
|---|
Enter any two of distance, time, and pace — the calculator solves for the third. You get your pace per kilometre and per mile, average speed, and a split chart showing your cumulative time at each kilometre or mile marker. Works for running, cycling, swimming, or walking, with one-tap presets for 5K, 10K, half marathon, and marathon.
How it works
- 1 Choose what to solve for Pick Pace, Time, or Distance. The two remaining fields stay editable; the solved one is computed for you and greyed out.
- 2 Enter your two known values Type the distance (or tap a race preset like 5K or marathon), then fill in the time or pace. Units can be kilometres or miles.
- 3 Read the results and splits The cards show pace per km, pace per mile, speed, and total time. The split table below lists your cumulative time at each distance marker — useful for pacing a race evenly.
Your data stays private
All processing happens entirely in your browser. No files, text, or data are ever sent to our servers. You can disconnect from the internet and this tool will still work.
Frequently asked questions
- How is running pace calculated?
- Pace is time divided by distance. Run 10 km in 55 minutes and your pace is 55 ÷ 10 = 5.5 minutes, i.e. 5:30 per kilometre. The calculator does the same in reverse: pace × distance gives finish time, and time ÷ pace gives distance.
- What's the difference between pace and speed?
- Pace is minutes per unit of distance (5:30 min/km); speed is distance per hour (10.9 km/h). Runners think in pace because race targets are set that way; cyclists usually think in speed. The calculator shows both.
- How do I convert pace per km to pace per mile?
- Multiply by 1.609. A 5:00 min/km pace is 5 × 1.609 ≈ 8:03 min/mile. The calculator shows both figures side by side, so there's no need to do the conversion by hand.
- What are the exact half marathon and marathon distances?
- A marathon is 42.195 km (26.219 miles) and a half marathon is 21.0975 km (13.109 miles). The preset buttons use these exact figures, so a 4-hour marathon works out to 5:41 min/km, not the 5:43 you'd get from rounding to 42 km.
- Does anything get sent to a server?
- No. The math runs entirely in your browser — nothing you type is uploaded, stored, or tracked.
From the blog
Race Pace Math: Splits, Conversions, and Common Mistakes How to work out the pace you need for a target finish time, convert between min/km and min/mile, and use split charts to avoid going out too fast. Read the post →Related tools
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