Work out your pace from any run, predict your race time, and get the exact paces to train at. Everything runs in your browser — nothing is uploaded, nothing is stored.
Enter a distance and a time to get your pace per kilometre and per mile.
Based on a recent race or time trial, using the Riegel formula — the standard endurance prediction model. Predictions are estimates, not guarantees.
Enter a recent race time and get the paces to train at. Most runners run their easy days far too fast — this is the fix.
The single most common mistake in running is doing easy runs at a moderate pace. It feels productive. It isn't — it leaves you too tired for the sessions that actually make you faster, and it is one of the main reasons new runners get injured. Your easy pace should feel almost embarrassingly slow. If you can't hold a conversation, slow down.
Your pace on any given day depends on sleep, heat, hills, wind and how your legs feel. Train by effort and let the pace be whatever it is. Use these calculators to understand your training, not to chase a number on a watch.
The Riegel formula assumes you have trained for the distance you're predicting. If you can run a fast 5K on 20 km a week, that does not mean you can run a marathon on the same training. Longer races also depend far more on fuelling and hydration — factors no formula can see.
When you build mileage, increase your weekly distance by no more than about ten percent, and take a cutback week every fourth week. Your heart and lungs adapt in weeks; your tendons and bones take months. That mismatch is where most running injuries come from.
Three things make a real difference to how running feels. Everything else is optional.
The only genuinely essential purchase. Replace them every 500–800 km — worn shoes are a leading cause of shin and knee pain.
See running shoes →You don't need a top-end model. Any watch that shows pace and distance is enough to follow a training plan.
See running watches →Not a cure for anything, but two minutes on tight calves genuinely helps how your legs feel the next day.
See foam rollers →These are plain links to Amazon search results. We are not currently enrolled in any affiliate programme, so we earn nothing from them — they are here because the advice is honest, not because we get paid.
An 8-week run-walk plan for total beginners. Three runs a week, no gym, no experience needed.
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