Heart Rate Zone Calculator
Enter your age and optional resting heart rate to get your five training zones in beats per minute.
Train at the right intensity
Heart-rate zones turn "easy" and "hard" into numbers you can hold to. This calculator estimates your maximum heart rate with the Tanaka formula — 208 minus 0.7 times your age, more accurate for most adults than the old 220-minus-age rule — then divides it into five training zones.
Add a resting heart rate and it switches to the Karvonen method, which personalises the zones to your fitness using your heart-rate reserve. A 35-year-old, for instance, gets a max near 183 bpm and an easy zone-2 window of roughly 110–128 bpm.
Private and instant
The zones update live as you type, and every calculation happens in your browser — nothing you enter is uploaded.
Frequently Asked Questions
How are the heart-rate zones calculated?
From your maximum heart rate. The tool estimates max HR with the Tanaka formula (208 − 0.7 × age), then splits it into five zones at 50–60%, 60–70%, 70–80%, 80–90%, and 90–100%.
What is the Karvonen method?
It personalises zones using resting heart rate — target = ((maxHR − restingHR) × %) + restingHR. Enter a resting rate and the tool uses it; leave it blank for the simpler percentage-of-max method.
Which zone should I train in?
Zone 2 (easy, 60–70%) builds aerobic base and should make up most training; zones 4–5 are hard intervals used sparingly. Balance matters more than always going hard.
Is my data private?
Yes. The zones are computed in your browser and nothing you enter is uploaded.
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