How to Calculate Max Heart Rate (Formulas by Age)

The simplest way to calculate max heart rate is to subtract your age from 220. For a 45-year-old, that gives 175 beats per minute (bpm). It is an estimate, and the American Heart Association (AHA) treats it as an average that individual people can miss.

This guide covers the classic formula, three better-tested equations, how to turn your number into training zones, and when a supervised test beats any math. The zone figures come from the AHA and the Centers for Disease Control and Prevention (CDC).

This article is general education, not medical advice. Check with a physician before starting or changing an exercise program, especially if you have a heart condition, take heart-rate-altering medication, or have been inactive for a long time.

The Classic 220 Minus Age Formula

Take 220 and subtract your age in years. A 30-year-old lands at 190 bpm, and a 60-year-old lands at 160 bpm. The AHA still uses this formula as the baseline for its target heart rate zones.

The equation traces back to a 1970 observation by researchers Samuel Fox and William Haskell, not to a controlled study of healthy adults. Exercise scientists Robergs and Landwehr reviewed its history in a 2002 paper in the Journal of Exercise Physiology Online and found no solid statistical basis behind it. That explains why it works as a fast starting point but not as a precise measurement.

The error grows at the ends of the age range. The formula tends to overestimate the maximum for younger adults and underestimate it for older ones. For a 65-year-old, it gives 155 bpm, while the Tanaka equation below gives about 163.

More Accurate Max Heart Rate Formulas

Research teams have tested newer equations on much larger groups. Each of these flattens the age slope compared with the classic formula.

The Tanaka equation came from a 2001 meta-analysis of more than 18,000 people in the Journal of the American College of Cardiology. It is the most common replacement for 220 minus age. Gellish and colleagues reached a nearly identical result in a 2007 study in Medicine & Science in Sports & Exercise.

Women often get a better number from the Gulati equation. It came from the St. James Women Take Heart Project, which followed more than 5,000 women without heart symptoms and was published in Circulation in 2010. The Nes equation comes from the Norwegian HUNT study (Scandinavian Journal of Medicine & Science in Sports, 2013) and works as a useful cross-check for people who exercise regularly.

Worked Example: One 45-Year-Old, Several Answers

Here is how the equations compare for a 45-year-old. The classic formula gives 175 bpm. Tanaka gives about 177, Gellish about 176, and Nes about 182. For a woman, Gulati gives about 166.

That spread matters. A 45-year-old woman using 220 minus age would set her ceiling about 9 bpm higher than the Gulati equation predicts. Her “moderate” zone could end up harder than she intended.

A practical habit is to run two or three formulas and treat the result as a likely window, not a single exact point. If your answers fall between 166 and 182, you know your real maximum is probably in that neighborhood and not at either extreme.

Which Formula Should You Use?

For most adults, Tanaka is a sensible default because it was built from a large and varied sample. Women can use Gulati and compare it with Tanaka. People who have trained for years may find Nes closer to what their watch records during hard efforts.

Use 220 minus age if a coach, clinic, or program you follow already uses it. Consistency matters more than which equation you pick, because zones only work if you apply them the same way each week. Swapping formulas mid-program makes your effort levels hard to compare.

Why Every Formula Is Only an Estimate

Age explains a large share of maximum heart rate, but not all of it. Studies of the classic formula commonly report a spread of roughly 10 to 12 bpm around the predicted value (Robergs and Landwehr, 2002). Two healthy 45-year-olds can have true maximums of 165 and 190.

Genetics drive much of that difference. Fitness does not raise your maximum much either. A well-trained person usually shows a lower resting rate, not a higher ceiling.

Day-to-day conditions also move the numbers. Heat, dehydration, caffeine, poor sleep, and altitude can all change what you see on a given session. The activity matters as well, since maximum heart rate is often a few beats lower in cycling and swimming than in running.

How to Turn Your Number Into Heart Rate Zones

Once you have an estimate, zones tell you how hard to work. The AHA and CDC use slightly different percentages, so know which one your program follows.

The Percent of Max Method

The AHA defines moderate intensity as 50 to 70 percent of maximum heart rate and vigorous intensity as 70 to 85 percent. With a max of 175, that is about 88 to 123 bpm for moderate and 123 to 149 bpm for vigorous. The CDC sets moderate at 64 to 76 percent and vigorous at 77 to 93 percent, which works out to about 112 to 133 bpm and 135 to 163 bpm.

Both systems are accepted, so pick one and stay with it. New people to exercise or returning after time off often do better starting near the bottom of the AHA range. A clinician can tell you where to begin if you have health concerns.

The Heart Rate Reserve (Karvonen) Method

The Karvonen method uses your resting heart rate, which makes zones more personal. Subtract your resting rate from your max to get your heart rate reserve. Multiply that by your target percentage, then add the resting rate back. Finnish physiologist Martti Karvonen described the approach in 1957.

Take a max of 175 and a resting rate of 60. Your reserve is 115. At 70 percent, the math is 115 × 0.70 = 80.5, plus 60, or about 141 bpm. At 85 percent, your target is about 158 bpm.

To find your resting rate, count your pulse for 30 seconds right after waking, before you get out of bed, and double it. Repeat for three or four mornings and average the results. The AHA lists 60 to 100 bpm as the normal resting range for adults.

Testing Your Actual Max Heart Rate

The most reliable method is a graded exercise test, usually on a treadmill or stationary bike while a clinician monitors an electrocardiogram. The intensity rises in stages until you cannot continue. Hospitals, cardiology clinics, and university exercise labs offer these tests.

Pushing to exhaustion on your own carries more risk than most people assume. Adults with heart disease, unexplained chest discomfort, or a long sedentary stretch should not attempt an all-out test without medical clearance. If you have been cleared, experienced athletes sometimes find their peak during a hard race or hill repeat while wearing a chest strap. Use the highest reading across several efforts and discard spikes that look wrong.

If you want a free way to check intensity, use the talk test the CDC describes. At moderate intensity, you can talk but not sing. At vigorous intensity, you can say only a few words before pausing for breath.

When Heart Rate Zones Do Not Work Well

Beta blockers and some other medications lower heart rate on purpose, so any formula can overstate what you can reach. The AHA advises people on these medicines to ask their doctor how to set targets. Many are guided by perceived exertion instead, using the Borg scale from 6 to 20 or a simple 0 to 10 scale.

Heart rhythm disorders, pregnancy, and thyroid conditions can also make heart rate a poor guide. Ask your clinician which measure to use in those cases.

Tracking Your Heart Rate During a Workout

Chest straps that read the heart’s electrical signal tend to follow fast changes more accurately than wrist sensors. Wrist-based optical sensors work fine for steady efforts but can lag during intervals. Cold hands, a loose fit, and tattoos can throw them off.

With no device, count your pulse at the wrist or neck for 30 seconds and multiply by two. Recheck your resting and exercise numbers every few months. Resting rate often drifts lower as fitness improves, which shifts any reserve-based zones.