How it’s calculated
Pace is the time taken per unit of distance, the reciprocal of speed. It is shown as minutes:seconds per kilometer or per mile (1 mile = 1.609344 km exactly).
Example: 5 km in 25:00. Pace = 1,500 s ÷ 5 km = 300 s/km = 5:00 /km. Per mile: 300 × 1.609344 = 482.8 s = 8:03 /mi. Speed = 5 km ÷ (25/60 h) = 12 km/h.
Predicting a finish: 5 km at 5:30 /km = 330 s × 5 = 1,650 s = 27:30.
Frequently asked questions
How do I convert pace per km to pace per mile?
Multiply the pace in seconds by 1.609344. For example 5:00 /km (300 s) × 1.609344 = 482.8 s ≈ 8:03 /mi.
What pace do I need for a sub-4-hour marathon?
4 hours over 42.195 km is 14,400 ÷ 42.195 = 341.3 s, or about 5:41 /km (9:09 /mi).
Does this account for hills or fatigue?
No. It assumes an even pace over the whole distance.
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Sources
- University Physics Volume 1, §3.1 Position, Displacement, and Average Velocity — OpenStax
- SI Units: Length — U.S. National Institute of Standards and Technology
Formulas are taken from the free public references above. Results are provided “as is” for informational and educational purposes only. See our disclaimer.
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