Running Pace Calculator

Divide the time by the distance. Fifty minutes for 10 km is 300 seconds per kilometre, which is 5:00 per km.

Multiply by 1.609. A 5:00 per km pace is 8:03 per mile, and going the other way divide by the same factor.

Because pace is a reciprocal of speed. Running one kilometre at 4:00 and another at 6:00 averages 5:00 only because the distances are equal — over equal times it would not.

Most training should be comfortably conversational, considerably slower than race pace, with a small proportion of hard work. The common error is running easy days too fast and hard days too slow.

Practise it. Most runners start faster than intended and fade, which costs more time late than the fast start gained early. A watch helps and pacing by effort helps more.

Roughly the fastest pace sustainable for about an hour — around 10 mile to half marathon race pace for most runners. It is a key training zone because it shifts the point at which fatigue accelerates.

It varies enormously with age, sex and training, and comparison is only meaningful within a category. Your own trend over months is more informative than any benchmark.

Most coaches suggest around 80% easy and 20% hard. The common error is running easy days too fast, which leaves too little capacity for the hard sessions to be hard.

Structuring training by heart rate ranges rather than pace, which self-corrects for heat, hills and fatigue. It needs a reasonably accurate maximum heart rate to be meaningful.

Blood is diverted to the skin for cooling, so less is available to working muscle. A hot day can slow marathon pace by several percent and it is not a fitness problem.

Usually a little easier, since there is no air resistance and no variation in surface. A 1% incline is the conventional adjustment to approximate outdoor effort.

Steps per minute, often around 170 to 180 for efficient runners. Increasing it slightly tends to reduce overstriding, which is one of the more reliable technique adjustments.