Pace Calculator
Enter any two of pace (min/km or min/mile), elapsed time, and distance — the third drops out, plus your average speed. Switch between metric and imperial and the distance converts in place. Built-in presets cover the standard race distances so you can quickly answer questions like "what pace do I need to break 50 minutes at 10K?" or "how far do I run in 45 minutes at a 5:30 pace?"
Pace
5:00 /km
Time
50:00
Avg speed
12.00 km/h
Linear projection — actual race times for longer distances usually run slower than this from fatigue.
How to use
- Pick which value you want computed: pace, time, or distance.
- Fill in the remaining two fields.
- Read pace, time, and average speed in the output cards. The computed field is highlighted.
Frequently asked questions
- Why does my pace look slower in imperial?
- A mile is longer than a kilometer, so the same speed produces a larger min/mile number than min/km. The cards always show pace in the unit you've selected.
- Marathon distance — 42.2 or 42.195?
- The marathon preset uses 42.195 km exactly (26.2 miles is a rounding). Same for the half at 21.0975 km.
- Does this account for walk-run intervals?
- No. Pace, time, and distance are linked by a single average speed. For interval planning, compute each segment separately.
- How accurate is the time-from-pace projection?
- Linear projection assumes you hold the pace. Real races slow down in the second half — a marathon based on your 10K pace will usually finish 5-10% slower.
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