Max heart rate
calculator

Enter your age and see all four published max heart rate formulas at once. The useful part isn't which one you pick — it's that any age estimate can be about 20 bpm off for a given person, which this page shows next to the numbers.

What max heart rate is

Your maximum heart rate (HR_max) is the highest rate your heart reaches during all-out effort. It is set mostly by age and genetics, falls slowly as you get older, and — contrary to a common belief — is not raised by getting fitter. Training lowers your resting heart rate and lifts the pace you can hold at a given heart rate; it leaves the ceiling roughly where it was.

You can't read HR_max off a formula exactly. The age equations below estimate the average maximum for a given age, which is a useful anchor for setting training zones and a poor substitute for a measured value when precision matters.

How the math works

Every common formula is a straight line in age: a starting number minus a slope times your age. Four are worth knowing, each from a primary publication.

• Fox, 220 − age (1971). The famous one, and the weakest. Fox, Naughton and Haskell drew it as a regression line through about ten compiled studies; it was never a validated predictive model. Robergs and Landwehr (2002) put its standard error of estimate at 7–12 bpm.
• Tanaka, 208 − 0.7 × age (2001). From a meta-analysis of 351 studies (18,712 subjects) plus a laboratory check on 514 adults, correlating with age at r = −0.90 and the same for men and women. Its standard error of estimate is about 10 bpm. This is the number the calculator leads with.
• Gellish, 207 − 0.7 × age (2007). A longitudinal fit to 908 exercise tests from 132 adults tracked over roughly 25 years — the same slope as Tanaka, a point lower.
• Nes / HUNT, 211 − 0.64 × age (2013). From 3,320 healthy adults in the HUNT Fitness Study, standard error of estimate 10.8 bpm. Its shallower slope runs higher than the others and found that the older equations underestimated measured HR_max in people over 30.

Worked example

Max heart rate is a beats-per-minute estimate from age in years, so there's no imperial-versus-metric version — a beat per minute and a year are the same everywhere.

A 40-year-old: the formulas agree, the person varies

• Fox: 220 − 40 = 180 bpm
• Tanaka: 208 − 0.7 × 40 = 180 bpm
• Gellish: 207 − 0.7 × 40 = 179 bpm
• Nes / HUNT: 211 − 0.64 × 40 = 185 bpm

The four land between 179 and 185 bpm — a spread of about 6 bpm. The individual error dwarfs it: with Tanaka's ~10 bpm standard error, about 95% of 40-year-olds fall within roughly ±20 bpm of 180, a true max anywhere from 160 to 200 bpm. The gap between people is about six times the gap between formulas.

A 60-year-old: the formulas pull apart

• Fox: 220 − 60 = 160 bpm (lowest)
• Gellish: 207 − 0.7 × 60 = 165 bpm
• Tanaka: 208 − 0.7 × 60 = 166 bpm
• Nes / HUNT: 211 − 0.64 × 60 = 173 bpm (highest)

Now the spread is 160–173 bpm, about 13 bpm — double the age-40 gap, because the formulas cross near age 40 and diverge on either side. The ±20 bpm individual band around Tanaka's 166 (146–186 bpm) still swamps it, and Fox, sitting lowest, is the one that most underestimates an older adult's measured maximum.

When this calculator is wrong

Heart-rate-max formulas have an error band that makes them less useful than they look. The classic 220 − age (Fox 1971) carries a population standard deviation of about 10–12 bpm; Tanaka's 208 − 0.7 × age is slightly tighter but still off by 5–8 bpm for many people. The practical consequence: a training zone built from a formula-estimated HR_max is sometimes a full zone away from a person's real zone, and when accuracy matters the right move is a max test (or a lab value) rather than trusting the equation.

The counter-case: for a new runner just starting out, the formula is fine for a first pass and saves the effort of a max test they probably aren't ready for. Estimate, train for a few weeks, and let the way your pace and perceived effort line up at each heart rate tell you whether the ceiling needs correcting.

• The number is a population average, not your ceiling. The equations predict the mean HR_max for an age. Plenty of healthy people sit 15–20 bpm above or below the line with nothing wrong — which is why a single formula number can't set a precise zone.
• The error is directional with age. The formulas cross near 40, so 220 − age tends to run high for younger adults and low for older ones (Nes/HUNT found the older equations underestimated measured HR_max over age 30). Pick the formula that was fit on people like you, and treat the band as asymmetric at the extremes of age.
• It doesn't apply to children, and it's not a heart screen. These equations were validated on adults. A child's maximum should come from a clinician, and a maximum that is wildly off the estimate — or exercise symptoms — belongs with a doctor, not a recompute.

What to do with the result

Use the estimate to set starting zones, then calibrate. Feed the Tanaka number into the heart rate zones calculator or, if you know your resting heart rate, the Karvonen calculator, which builds zones from your heart rate reserve and is less sensitive to a small HR_max error. Train for two to three weeks and watch whether the zones feel right — if your "easy" Zone 2 forces walking breaks, or your "threshold" work feels trivial, your real HR_max is probably off the estimate and the zones need nudging.

When the number genuinely matters — interval prescriptions, racing off heart rate — measure it. A hard, properly warmed-up effort to true exhaustion (a steep hill repeat or a progressive treadmill ramp, ideally supervised if you're older or deconditioned) reads your actual peak far better than any age line. If you'd rather train off a lower, safer aerobic ceiling, the MAF calculator sets one from age without needing a max at all.

Common questions

How do I calculate my max heart rate?

Take your age and subtract it from a formula. The best-validated general one is Tanaka's 208 − 0.7 × age; the familiar 220 − age (Fox) is simpler but less accurate. For a 40-year-old, Tanaka gives 208 − 28 = 180 bpm. Treat the result as an average for your age, not your exact ceiling — the individual spread is about ±20 bpm.

Is 220 minus age accurate?

Not very. It began as a line drawn through a handful of studies in 1971, not a tested predictive model, and its standard error of estimate is 7–12 bpm (Robergs and Landwehr 2002). It tends to run high for younger adults and low for older ones. Tanaka's 208 − 0.7 × age is a better default, though every age formula carries a wide individual band.

Which max heart rate formula is most accurate?

For a general adult population, Tanaka (208 − 0.7 × age) is the best-validated, drawn from a meta-analysis of 351 studies and cross-checked in the lab. The HUNT equation (211 − 0.64 × age) fits older adults better, since the earlier formulas underestimated measured max heart rate over age 30. But the honest answer is that the choice moves the estimate by only a few beats — far less than the ±20 bpm a given person varies — so a measured test beats all of them when it counts.

How do I measure my real max heart rate?

With a maximal effort, not a formula. After a thorough warm-up, do a progressively harder effort to genuine exhaustion — repeated hard hill climbs or a treadmill ramp — while wearing a chest-strap monitor, and take the highest reading. It's demanding, so get medical clearance first if you're older, new to training, or have any cardiac history. A supervised graded exercise test is the lab version.

Does max heart rate change with fitness?

Barely. Max heart rate is set mostly by age and genetics and drifts down slowly over the years; training doesn't raise it. What improves is everything below the ceiling — a lower resting heart rate, and more pace or power at the same heart rate. If your measured max rises after training, it usually means the first test wasn't a true maximal effort.

Is a higher max heart rate better?

No. Max heart rate isn't a fitness score — two equally fit people of the same age can have maxes 20 bpm apart with no performance difference. It's just the top of your personal range, used to anchor training zones. Resting heart rate, heart rate recovery and the pace you hold at a given heart rate are the numbers that track fitness.