Maximum Heart Rate Calculator
Almost every heart rate zone you have ever been given rests on this one estimate — and the version most people use was never based on research.
Where 220 − age came from
It was not a study. In 1971 Fox, Naughton and Haskell plotted around ten sets of previously published data, eyeballed the trend, and noted informally that maximum heart rate fell by roughly one beat per year from about 220. There was no regression, no error estimate, and no validation. The line was offered as a convenience.
Fifty years later it is printed on treadmill consoles worldwide. Its problems are well documented: it overestimates maximum heart rate in young adults and underestimates it in older ones, and its standard deviation is around 12 bpm — meaning that for roughly one person in three, the true value is more than a full training zone away from the estimate.
The better formulas
Tanaka's is the sensible default: it rests on by far the largest evidence base and behaves well across the adult age range. Gulati's matters because the classic formula performs worst in women, where it consistently overestimates — which in a clinical stress test can mean a woman is judged to have reached a lower percentage of maximum than she really has.
Even the best of these carries an individual standard deviation of about 10–12 bpm. Genetics dominate: two untrained 45-year-olds can genuinely differ by 30 bpm.
Measuring it for real
If precision matters — for structured training or a clinical purpose — measure it rather than estimate it. The highest reading from a genuinely maximal effort beats any equation.
- Field test. After a thorough 15-minute warm-up, run or cycle 3 minutes hard, recover 2 minutes easy, then 3 minutes all-out, finishing with a sprint. The peak recorded on a chest strap is close to your true maximum.
- Race data. The highest heart rate you have recorded in the closing minutes of a hard 5 km or similar is usually within a beat or two.
- Laboratory test. A graded exercise test with ECG monitoring is the gold standard and the only sensible option if you have any cardiovascular risk.
Do not attempt a maximal test if you are new to exercise, are over 40 without a recent check-up, or have any diagnosed heart condition, uncontrolled hypertension or symptoms such as chest pain, palpitations or unexplained breathlessness. Get medical clearance first.
Note also that maximum heart rate is sport-specific: most people record 5–10 bpm lower cycling than running, and lower again swimming, because less muscle mass is involved.
Frequently asked questions
Does a higher maximum heart rate mean better fitness?
No. Maximum heart rate is largely genetic and declines with age regardless of training. Fitness shows up in resting heart rate, which falls with training, and in how quickly heart rate recovers after effort. Two athletes of identical ability can have maxima 30 bpm apart.
Why does my watch record a higher figure than this?
Either your true maximum is genuinely above the estimate — quite common — or the optical sensor glitched. Wrist sensors sometimes latch onto cadence or double-count during high-intensity intervals. A chest strap is far more reliable at the top end. If a high reading is repeatable across sessions, trust it over the formula.
Does maximum heart rate fall if I stop training?
Slightly, but the age-related decline continues whether you train or not. Detraining affects resting heart rate, stroke volume and VO₂ max far more than it affects maximum heart rate.