Heart Rate Zone Calculator
Calculate your five heart-rate training zones from age, with the more accurate Karvonen method when you add resting heart rate.
Last reviewed by the Radiatus Cloud team
Max HR estimated as 220 − age. With a resting HR, zones use the Karvonen (heart-rate reserve) method: target = rest + intensity × (max − rest). Educational only — not medical advice.
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Find your heart-rate training zones
Training zones structure exercise by intensity, and they are based on your heart rate. This calculator computes your five heart-rate training zones from your age, using the more accurate formula.
Why zones structure training
Different goals need different intensities, and heart-rate zones make intensity measurable: lower zones for easy, sustainable effort and fat burning, middle zones for building cardiovascular fitness, higher zones for peak performance intervals. The zones are percentages of your maximum heart rate, which is estimated from age. Using a more accurate age-based formula than the simple one gives better zone boundaries. Training to zones, rather than by feel alone, lets you hold the right intensity for each session’s purpose.
A fitness estimate
This is an estimate from a standard formula for general information, not medical advice; individual health depends on far more than any single number, so consult a professional for anything that matters. It runs entirely in your browser, so nothing you enter is uploaded, keeping your figures on your own machine.
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Frequently Asked Questions
What are heart-rate training zones?
Ranges of heart rate corresponding to exercise intensity, from easy fat-burning effort to peak intervals, each suited to a different training goal.
How are the zones calculated?
As percentages of your estimated maximum heart rate, which is derived from your age using an age-based formula.
Why five zones?
Because they span the useful range of intensity, letting you match effort to goal: recovery, endurance, fitness-building, and peak performance.
How accurate are age-based zones?
They give a reasonable estimate; individual maximums vary, so a measured maximum from a supervised test is more precise for serious training.
Is this medical advice?
No. It is a fitness estimate. Consult a professional before intense exercise.
Privacy & Security
Runs entirely in your browser. No data is sent to any server.
How to Use
Enter your age (and optionally resting heart rate). Your max HR and five training zones from recovery to peak update instantly.
Disclaimer: This tool is provided "as is" without warranty of any kind. Results are for educational and utility purposes.
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