Heart Rate Zone Calculator — training zones
Calculate your max heart rate and training zones 1–5 from age (and optional resting HR) — in your browser.
🔒 Runs entirely in your browser. Your input and output are never sent to a server or stored — fully private.
| Zone | Intensity | Heart rate |
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Estimates only — not medical advice.
About this tool
Training by heart rate keeps your effort honest, and this calculator maps out the five classic zones for you. Enter your age to estimate your maximum heart rate, optionally add your resting heart rate for a more personal result, and pick a formula. It then shows the beats-per-minute range for each zone, from easy recovery to all-out. Cyclists, runners and gym-goers use it to train at the right intensity. The zones are computed in your browser, so the figures you enter are never uploaded.
Frequently asked questions
How is maximum heart rate estimated?
The tool offers two formulas: the familiar 220 minus your age, and the Tanaka formula, 208 minus 0.7 times your age, which tends to fit older adults better. Both are population averages, so your true maximum could be 10 to 20 beats higher or lower. A proper lab or field test is the only way to know it exactly.
What is the Karvonen method?
Karvonen bases the zones on your heart-rate reserve — your maximum heart rate minus your resting heart rate — rather than on max alone. A zone is then your resting rate plus a percentage of that reserve. Because it factors in your resting rate, which improves with fitness, it usually gives more personal and slightly higher targets, which is why the resting-rate field is worth filling in.
What do the five zones mean?
Roughly: zone 1 (50 to 60 percent) is very light recovery; zone 2 (60 to 70) builds aerobic base and burns fat; zone 3 (70 to 80) is steady aerobic work; zone 4 (80 to 90) is hard threshold effort; and zone 5 (90 to 100) is maximal. These are estimates for general fitness, not medical guidance — see a doctor before intense exercise if you have any heart concerns. All of it runs in your browser.