Maximum heart rate (MHR) is the fastest your heart can beat during all-out physical effort, and it drops predictably as you age. The most widely used formula estimates it as 220 minus your age, giving a 30-year-old an estimated max of 190 beats per minute and a 50-year-old a max of 170. But that formula has real limitations, and your actual max could be 20 to 30 beats per minute higher or lower than what the math predicts.
Estimated Max Heart Rate by Age
Here are the numbers the standard 220-minus-age formula produces:
- 20 years old: 200 bpm
- 25 years old: 195 bpm
- 30 years old: 190 bpm
- 35 years old: 185 bpm
- 40 years old: 180 bpm
- 45 years old: 175 bpm
- 50 years old: 170 bpm
- 55 years old: 165 bpm
- 60 years old: 160 bpm
- 65 years old: 155 bpm
- 70 years old: 150 bpm
These numbers are a starting point, not a ceiling. The standard deviation around any age-predicted max is roughly 10 beats per minute, meaning about a third of people fall outside that range on either side. Two healthy 45-year-olds could have true maximums of 165 and 190, and both would be perfectly normal.
Where the 220-Minus-Age Formula Comes From
Fox and Haskell proposed this equation in the 1970s after reviewing about 10 studies. By the authors’ own description, the formula was determined “arbitrarily.” Most of the subjects were 55 or younger, and none were older than 65. That matters because the formula tends to overestimate max heart rate in younger adults and increasingly underestimates it in older adults. By age 70, the gap between the old formula and newer regression data is about 10 beats per minute, and for some individuals the underestimate can exceed 20 bpm.
The formula stuck around because it’s easy to remember and doesn’t require any equipment. Clinicians, fitness trainers, and exercise apps all default to it. But “easy” and “accurate” aren’t the same thing.
The Formula Is Different for Women
The 220-minus-age equation was built almost entirely from studies of men. A large study of 5,437 healthy women (the St. James Women Take Heart Project) produced a more accurate formula for women: 206 minus 88 percent of age.
The practical difference grows with age. At 50, the traditional formula gives 170 bpm for everyone, while the women-specific formula gives 162 bpm. That 8-beat gap changes where your training zones fall. If you’re a woman using the standard formula, you may be chasing a target heart rate that’s set too high, which can make moderate exercise feel harder than it should or lead you to think you’re underperforming when you’re not.
How Athletes Differ
A common assumption is that fit people have higher max heart rates. The opposite is actually true: trained athletes tend to have slightly lower maximums than sedentary people of the same age. In research comparing the two groups, sedentary individuals averaged about 195 bpm at age 23, while aerobic and anaerobic athletes averaged closer to 190 bpm.
The rate of decline with age, however, is similar regardless of fitness level. Training doesn’t slow down the annual drop in max heart rate. What training does change is resting heart rate, stroke volume (how much blood your heart pumps per beat), and how efficiently your body uses oxygen. Those adaptations matter far more for performance than your maximum number.
There is a notable sex difference in how fast max heart rate declines. Research found that women lose about 1.1 beats per minute per year of age, while men lose roughly 0.55 beats per minute per year. Predictive equations for athletes reflect this: 202 minus 0.55 times age for men, and 216 minus 1.09 times age for women.
Why Your Actual Max May Not Match
Individual variability is the biggest reason formulas fall short. Among people of the same age, true max heart rate can vary by 20 to 30 bpm depending on the equation used and the person’s genetics, body size, and cardiovascular makeup. No formula accounts for all of these factors.
Medications are another major variable. Beta blockers, commonly prescribed for high blood pressure and certain heart conditions, directly slow heart rate. If you take one, you may never reach the target your formula predicts, no matter how hard you push. There’s no standard adjustment factor because the effect varies from person to person. If you’re on a beta blocker and want to train by heart rate, an exercise stress test can establish your personal ceiling. Otherwise, a perceived exertion scale (rating how hard you feel you’re working on a numeric scale) is a more reliable guide than any heart rate number.
How Max Heart Rate Is Measured Directly
The gold standard for confirming true maximal effort involves measuring the ratio of carbon dioxide your body produces to the oxygen it consumes during an all-out exercise test. When that ratio exceeds 1.10, it confirms you’ve genuinely reached your limit. This requires specialized lab equipment that most gyms and clinics don’t have, which is why age-based formulas remain the default.
Standard exercise stress tests use heart rate as a proxy. Clinicians typically aim for 85% of your age-predicted max to consider the test adequate. But research shows that only about half of people who hit 85% of their predicted max have actually reached true maximal effort by the gas-exchange standard. That’s a significant gap, and it reinforces how rough the age-based estimates really are.
Using Max Heart Rate for Exercise
The American Heart Association recommends training in two broad zones based on your estimated max. Moderate-intensity exercise falls between 50% and 70% of max heart rate. Vigorous-intensity exercise sits between 70% and 85%.
For a 40-year-old using the standard formula (max of 180 bpm), moderate exercise means keeping your heart rate between 90 and 126 bpm, while vigorous exercise means 126 to 153 bpm. If you’re a 40-year-old woman using the more accurate formula, your estimated max is 171 bpm, shifting those zones down by about 5 beats at each boundary.
These zones are useful for pacing yourself, but treat them as guidelines rather than hard limits. If you feel like you’re working hard at a heart rate below your calculated zone, trust your body. If a formula says you should be gasping at 160 bpm but you feel fine, your personal max is likely higher than the estimate. Over time, paying attention to both the number on your wrist and how you actually feel gives you a more accurate picture than either one alone.