How it works
pace = time ÷ distance
Average pace is simply the elapsed time divided by the distance covered — the kinematic definition of speed, inverted so it reads as minutes per unit. We compute everything in SI units (metres and seconds) and only convert at the edge, so the mile and kilometre figures never drift apart by rounding. Speed is the same relationship expressed as distance over time (mph or km/h). The "per 400 m" line is your pace scaled to one track lap, and the marathon estimate assumes you hold this exact pace for the full 42.195 km — real races slow down, so treat it as a ceiling and use a race-time predictor for a realistic target.
Sources
- Definition of average pace Average speed = distance ÷ time (kinematics); pace is its inverse, expressed as time per unit distance.
- Marathon distance standard World Athletics — the marathon is exactly 42.195 km (26 mi 385 yd).
- Why holding even pace matters Riegel, P. S. (1981). “Athletic Records and Human Endurance.” American Scientist 69(3), 285–290.
FAQ
How do I calculate my running pace?
Divide your total time by the distance you covered. For example, 40 minutes over 5 miles is 40 ÷ 5 = 8:00 per mile. This calculator does it for both miles and kilometres at once.
What is a good running pace?
It depends entirely on your fitness and the distance. Recreational runners often sit around 9–12 min/mile (5:30–7:30 min/km) for easy runs; faster for shorter races. There is no universal "good" pace — compare against your own goals.
How do I convert pace between min/mile and min/km?
One mile is 1.609344 km, so a per-mile pace is faster-sounding than the same effort per km. Multiply a min/mile pace by 0.6214 to get min/km, or divide by 0.6214 to go the other way. The calculator shows both so you never have to.
Does the marathon estimate mean I can run that time?
Not directly. It assumes you hold the entered pace for the entire 42.195 km, which is much harder over a marathon than over a short run. Use it as a "what if I never slowed down" ceiling, and a race-time predictor for a realistic goal.
How do I read pace per 400 m?
A standard outdoor track lap is 400 m. The per-400 m figure tells you how long one lap should take at your current pace — handy for track workouts and interval sessions.
Why do the mile and kilometre paces look so different?
Because a mile is longer than a kilometre, it takes more time to cover, so the min/mile number is always larger than the min/km number for the same effort. Both describe the identical speed.
Pace figures are mathematical and exact for the distance and time you enter. The marathon estimate is an even-pace projection, not a personalised prediction. General information for training, not medical or coaching advice.