Free Tool

Heart Rate Training Zone Calculator

Enter your age to estimate your maximum heart rate and see your five training zones in beats per minute. Add your resting heart rate for the more precise Karvonen (heart-rate-reserve) zones — the same method Garmin, Polar, Wahoo, and COROS use on-device.

Measure it first thing in the morning before getting up. Unlocks the Karvonen zones.

Enter your age and press Calculate zones to see your results.

How the numbers are calculated

Maximum heart rate. There is no way to know your exact max without a lab or field test, so this tool uses two published population formulas. The Tanaka formula (208 − 0.7 × age) comes from a 2001 meta-analysis and tracks measured max HR better across ages than the older 220 − age rule of thumb, which is shown only for comparison.

Five training zones. Zones are defined as standard percentage bands of your max heart rate: Zone 1 (50–60%), Zone 2 (60–70%), Zone 3 (70–80%), Zone 4 (80–90%), and Zone 5 (90–100%). This is the common 5-zone model used by mainstream training platforms.

Karvonen / heart-rate reserve. When you enter a resting heart rate, each zone is recalculated as (max HR − resting HR) × zone% + resting HR. Because it accounts for your resting HR, it shifts the zone ranges to fit your fitness — the same reserve method your Garmin, Polar, Wahoo, or COROS watch uses on-device.

Sources: Tanaka H, Monahan KD, Seals DR. “Age-predicted maximal heart rate revisited.” Journal of the American College of Cardiology, 2001. Karvonen MJ, Kentala E, Mustala O, 1957.

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A note on this estimate. These numbers are training estimates derived from published, population-level formulas (Tanaka 2001 and Karvonen 1957) — not measured values and not medical advice. Individual max heart rate varies. If you have a heart condition, take medication that affects heart rate, or are starting a new program, talk to a qualified healthcare professional first.