How to Calculate Maximum Heart Rate and Training Zones

The quickest way to estimate your maximum heart rate is 220 minus your age, so a 40-year-old gets 180 beats per minute (bpm). A more recent formula, 208 minus 0.7 times your age (the Tanaka formula), tends to be closer for older adults. Both are population averages: your true maximum can easily be 10 or more beats higher or lower, so treat the result as a starting point for setting training zones, not a precise number.

What is maximum heart rate?

Maximum heart rate is the highest rate your heart can reach during an all-out effort. It is mostly set by age and genetics, and it falls gradually as you get older. Unlike resting heart rate, it does not change much with training - a fitter person is not someone with a higher maximum, but someone who can work harder at any given heart rate. It is also not a target: you do not need to reach it to get fitter.

Formulas for estimating maximum heart rate

220 minus age

Max HR = 220 - age. Simple and widely used, including by the American Heart Association for its target heart rate guidance. It was not originally derived from a large, rigorous study, and research has found it tends to underestimate maximum heart rate in older adults.

Tanaka formula

Max HR = 208 - (0.7 x age). Published in 2001 from a meta-analysis of 351 studies covering 18,712 people, then checked in a separate laboratory study. The authors found it worked equally for men and women and regardless of how active people were.

Gellish formula

Max HR = 207 - (0.7 x age). From a study that followed the same people through repeated maximal exercise tests over 25 years. It gives results almost identical to Tanaka.

HUNT formula

Max HR = 211 - (0.64 x age). From a Norwegian study of 3,320 healthy adults whose maximum heart rates were measured in exercise tests. It predicts slightly higher values for middle-aged and older people than the other formulas.

Working it out by hand

For a 50-year-old:

• 220 - 50 = 170 bpm
• 208 - (0.7 x 50) = 208 - 35 = 173 bpm
• 207 - (0.7 x 50) = 207 - 35 = 172 bpm
• 211 - (0.64 x 50) = 211 - 32 = 179 bpm

Here is how the formulas compare across ages (rounded to the nearest beat):

The formulas agree closely for younger adults and spread apart with age, where 220 minus age gives the lowest estimate.

How accurate are these formulas?

Each formula describes the average of a large group. Individuals scatter widely around that average: in the HUNT study, the typical error of an age-based prediction was about 11 bpm, meaning many people sit 10 or more beats above or below their predicted maximum. Two 40-year-olds could genuinely have maximums of 168 and 194.

Signs your estimate may be off:

• Easy runs or rides feel hard even at the low end of your estimated zones.
• You regularly see heart rates well above your estimated maximum during hard efforts.
• Hard intervals never get you near the upper zones even though you are working very hard.

If you are used to hard exercise, the highest reliable heart rate you have seen near the end of a hard race or a series of hard hill repeats gives a practical reference. A formal maximal exercise test, done under professional supervision, is the most reliable way to measure it.

Turning maximum heart rate into training zones

Percentage of maximum heart rate

Multiply your maximum by each percentage. The American Heart Association describes moderate intensity as about 50 to 70 percent of maximum and vigorous intensity as about 70 to 85 percent. Many training plans split this into five zones. For a maximum of 173 bpm:

Heart rate reserve (Karvonen method)

This method also uses your resting heart rate, so it adjusts for fitness:

Target heart rate = ((max - resting) x intensity) + resting

Example: max 173, resting 60. Heart rate reserve is 113. At 60 percent: (113 x 0.6) + 60 = 128 bpm. At 80 percent: (113 x 0.8) + 60 = 150 bpm. Note that a given percentage of heart rate reserve comes out higher than the same percentage of maximum, so do not mix the two systems.

For how runners put these zones to use week to week, see heart rate zone training for runners.

Use how you feel as a cross-check

The "talk test" is a simple partner to any formula. If you can talk but not sing, you are at a moderate effort; if you can only say a few words before pausing for breath, you are working vigorously. When your heart rate and how you feel disagree, adjust your zones over time rather than forcing the numbers.

When to stop exercising

Stop and seek medical help if you have chest pain or pressure, feel faint or dizzy, become unusually short of breath, or feel a heartbeat that is irregular or much faster than your effort explains.

Seeing your zones in FitRest

FitRest shows each workout saved to Apple Health with a breakdown of time spent in heart rate zones, so you can check whether a session matched what you planned. Top Intensity highlights your hardest efforts, and Cardio Recovery shows how quickly your heart rate falls in the minute after a workout. Learn more on the workouts feature page.

Sources

• Tanaka H, Monahan KD, Seals DR - Age-predicted maximal heart rate revisited (Journal of the American College of Cardiology, 2001)
• Gellish RL et al. - Longitudinal modeling of the relationship between age and maximal heart rate (Medicine and Science in Sports and Exercise, 2007)
• Nes BM et al. - Age-predicted maximal heart rate in healthy subjects: The HUNT fitness study (Scandinavian Journal of Medicine and Science in Sports, 2013)
• American Heart Association - Target Heart Rates Chart