Heart-rate zones calculator

Calculate your maximum heart rate (Tanaka, 220 − age, Gulati) and your five training zones, with the Karvonen method if you know your resting heart rate.

Heart profile

The result appears as soon as you enter your age. Resting heart rate switches to the Karvonen method; a measured max heart rate replaces the estimate.

Measured in the morning on waking, lying down, over one minute.

Max heart rate formula

From an exercise test or a heart rate watch; it replaces the age estimate.

Method & sources

Maximum heart rate is estimated from age with the chosen formula, or replaced by your measured value. Without resting heart rate, the five zones are 50–60%, 60–70%, 70–80%, 80–90% and 90–100% of max heart rate. With resting heart rate, those percentages apply to heart rate reserve (Karvonen method).

Formula
Tanaka: max HR = 208 − 0.7 × age · Karvonen: target HR = resting HR + intensity × (max HR − resting HR)

Limitations

  • An age formula does not predict one person’s max heart rate exactly: the gap can exceed 10 bpm.
  • Zone limits are practical references, not physiological thresholds measured in a lab.
  • Beta blockers and some conditions make these references unsuitable.