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Heart Rate Zone Calculator

Training zones from the Karvonen method — anchored to your resting heart rate, not just your age — with both published max-HR formulas shown so you can see how rough that estimate really is.

Your details

Age

Resting heart rate (bpm)Measure first thing in the morning, still in bed, for an honest number.

Your numbers

—BPM · EST. MAX (TANAKA 2001)

Classic 220 − age estimate, for comparison —

Zone 1 · Recovery — 50–60% HRR —

Zone 2 · Aerobic base — 60–70% HRR —

Zone 3 · Tempo — 70–80% HRR —

Zone 4 · Threshold — 80–90% HRR —

Zone 5 · Max effort — 90–100% HRR —

Fill your details — every step of the arithmetic appears here.

The math, shown

Max heart rate: the famous 220 − age line (Fox 1971) was never meant as a precision tool. Tanaka’s 2001 analysis of laboratory data found it overestimates max HR in young adults and underestimates it in older adults, and proposed 208 − 0.7 × age instead — the estimate this page anchors to. Both are shown above; any age formula misses real individuals meaningfully, so treat zones as bands, not walls.

The Karvonen method (1957): zones are set as a percentage of heart-rate reserve — max minus resting — then added back on top of resting. Two people the same age with different resting heart rates get different zones, which is exactly the point.

One hard caveat: if you have a heart condition or take medication that affects heart rate (beta-blockers, for example), formula-based zones do not apply to you — get zones from clinical testing instead.

These are population formulas — a starting point, not a prescription. Your training history, sleep, stress and cycle shift the real answer. That is what the 9-axis Body Scan measures.

Sources

Karvonen MJ, Kentala E, Mustala O. The effects of training on heart rate: a longitudinal study. Ann Med Exp Biol Fenn. 1957;35(3):307–315.
Fox SM, Naughton JP, Haskell WL. Physical activity and the prevention of coronary heart disease. Ann Clin Res. 1971;3(6):404–432.
Tanaka H, Monahan KD, Seals DR. Age-predicted maximal heart rate revisited. J Am Coll Cardiol. 2001;37(1):153–156.

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