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Running & Endurance Calculators

Pace, distance and time are closely connected, which makes a small set of running tools especially useful for planning a session or reviewing a race. Use these calculators to convert a target time into a pace, create even or negative splits and understand how a recent effort may translate to another distance.

Explore Running & Endurance Calculators

6 free tools

How to use these tools well

A predicted time is a planning range

Race-time and pace predictions use the information available to them, usually a previous result and a target distance. They do not know the course, weather, terrain, fuelling, injury history or how specific your training has been. Use a prediction to choose sensible targets, then adjust on the day using effort and conditions.

Keep easy days genuinely easy

Heart-rate zones, cadence and pace can provide useful guardrails, but no single metric is perfect for every runner. Heat, hills, fatigue and sensor accuracy can all alter the numbers. Combining pace with perceived effort and a gradual training progression is generally more practical than forcing every run into one exact target.

Link the run to the rest of your training

For longer events, use the marathon-fuel, water and carbohydrate tools alongside pacing calculations. For HYROX or mixed conditioning, include station splits and transition time rather than treating the running pace in isolation. Seek medical assessment for chest pain, unexplained breathlessness, fainting or other concerning symptoms during exercise.