Max heart rate calculator
Four published formulas at once, with what each one actually rests on — because the one everybody knows was never a study, and it happens to agree with the good ones at exactly the ages you would check it at. Nothing you type here leaves your browser — it is worked out on your own device, so there is nothing to send and nothing to log.
The famous one is the weakest one
“220 minus age” was never a study. It comes from Fox, Naughton and Haskell in 1971, who drew it from eleven small and largely unpublished datasets and offered it as a rule of thumb. It was not derived, it was not validated, and it is the only one of these four that most people have heard of.
The other three are not rules of thumb. Tanaka (2001) is a meta-analysis of 351 studies and 18,712 people. Nes (2013) measured 3,320 adults directly in the HUNT Fitness Study and found the real decline to be 0.64 beats a year rather than the 1.0 that 220 minus age assumes. Gulati (2010) measured 5,437 women, because the others were derived mostly from men and overestimate women’s maximum.
And it agrees with the good ones at exactly the ages you would check
This is the part worth staring at. Fox and Tanaka are both straight lines, so they cross once. Solve 220 − age = 208 − 0.7 × age and the answer is exactly 40.
Fox and Nes cross at exactly 25.
So if you sanity-check “220 minus age” against a properly derived formula at forty, or at twenty-five, you get perfect agreement and conclude there is nothing wrong with it. Check at twenty and Fox and Tanaka differ by 6 bpm; at seventy, by 9. Every other pair of these four crosses either at age 116 or at a negative age — which is to say, never in a human lifetime.
Picking a check value where two candidates happen to agree is a way of proving nothing while feeling thorough. The value worth testing is the one where they diverge most.
The disagreement is worse where it actually lands
Almost nobody wants a maximum heart rate for its own sake. They want a training zone, and a zone is a percentage of that maximum — so the disagreement is multiplied into the number people actually train by.
At seventy, the four formulas put the top of the easy zone 15 bpm apart. That is most of a zone’s width, decided entirely by which equation your watch’s manufacturer happened to choose.
Two things are both called “70 per cent”
A percentage of your maximum and a percentage of your reserve — the gap between your resting and maximum rates, which is Karvonen’s method — are different quantities that share a wording. They are both in the textbooks, and the reserve version gives a higher number at every zone.
If your watch and your coach disagree about what your easy pace should feel like, this is often why. Put your resting rate in above and the page will show you both.
What none of this can tell you
Your own maximum. Tanaka reports a standard deviation of about 10 bpm about the prediction for an individual, so two people of the same age can genuinely differ by 20 bpm and both be entirely normal.
Which of the two uncertainties is bigger depends on your age, and the answer is not the one we first wrote down. Up to about 63 the gap between two people is wider than the gap between the four formulas, so the formula you pick is the smaller worry. After 63 the formulas draw further apart than people do, and the choice starts to matter more than the person. That crossover is computed from the equations, not quoted.
So the four numbers on this page are a range of population averages, and your own figure sits somewhere in a wider band around them. The only way to know your actual maximum is to measure it, and measuring it means a maximal effort, which is not something a web page should be talking anybody into.
This page is arithmetic on published figures. It is not a medical assessment.
Where these came from
Fox, S. M., Naughton, J. P., & Haskell, W. L. (1971). Annals of Clinical Research 3: 404–432. · Tanaka, H., Monahan, K. D., & Seals, D. R. (2001). “Age-predicted maximal heart rate revisited.” Journal of the American College of Cardiology 37(1): 153–156. · Gulati, M. et al. (2010). “Heart rate response to exercise stress testing in asymptomatic women: the St James Women Take Heart Project.” Circulation 122: 130–137. · Nes, B. M. et al. (2013). “Age-predicted maximal heart rate in healthy subjects: The HUNT Fitness Study.” Scandinavian Journal of Medicine & Science in Sports 23(6): 697–704.
The crossing ages on this page are solved from the equations themselves rather than looked up, and the page reads the slope and intercept off each formula rather than holding a second copy of the constants.