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Fill in any two of pace, time and distance and this works out the third — so you can find the pace a target finish demands, the time a training run should take, or how far you went from your pace and duration. It also projects your likely finish times for the 5K, 10K, half marathon and marathon at whatever pace you put in.

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Pace / km
Pace / mile
Speed

🏅 Your Finish Times at This Pace

Assumes you hold the same pace throughout. Real race times typically slow slightly over longer distances.

Reading race predictions with a pinch of salt

Predicting a marathon time from a 5K pace is genuinely useful, but it rests on an assumption that's kinder on paper than on the road: that you can hold the shorter distance's effort over the longer one. In reality pace fades as distance grows, because endurance, fuelling and plain fatigue come into play — most runners slow by a noticeable margin between their 10K pace and their marathon pace.

A common rule of thumb is that each doubling of distance adds a few per cent to your per-mile time, which is why the predictions here are best read as an optimistic ceiling to train towards rather than a promise. Pace is worth thinking about in the right unit, too: minutes per mile or per kilometre tells you far more about a run than an average speed, which is why runners the world over talk in pace.

❓ Frequently Asked Questions

How do I calculate my running pace?

Pace is your time divided by distance. Choose "Find Pace", enter the distance you ran and your total time, and the calculator shows your pace per kilometre and per mile, plus your average speed. For example, running 10 km in 50 minutes is a pace of 5:00 per km.

What is a good pace for a beginner?

For many beginner runners, a comfortable pace is around 7:00–8:00 per km (roughly 11–13 min per mile). Pace is very individual — the key is being able to hold a conversation while running. Use the predictions to set realistic race-day goals.

What pace do I need for a sub-2-hour half marathon?

To finish a half marathon (21.0975 km) in under 2 hours you need to average about 5:41 per km (roughly 9:09 per mile). Switch to "Find Pace", enter 21.0975 km and a time of 2:00:00 to see it.

How accurate are the race time predictions?

They assume you hold exactly the same pace for the whole distance. In reality most runners slow down a little over longer distances, so your real marathon time is usually a bit slower than a straight pace multiplication suggests. Treat them as an optimistic target.

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