Heart rate zone calculator
Five training heart rate zones from your age and resting heart rate (Karvonen method).
Age formulas are rough averages, and your real maximum may differ by 10 or more beats. Check with a doctor before starting hard exercise.
How this calculator works
Karvonen: target = resting + intensity × (max − resting). Using your heart rate reserve makes the zones fit your fitness better than a straight percentage of maximum.
Worked example: age 40 (max 180) with a resting rate of 60 gives a reserve of 120, so zone 2 (60–70%) is 132–144 bpm.
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