Heart rate zone calculator

How this calculator works

Maximum heart rate is the fastest your heart is expected to beat during all out exercise. The familiar estimate is 220 minus age. The Tanaka equation is 208 minus 0.7 x age. Tanaka and colleagues built it from a meta-analysis of 351 studies and checked it in 514 healthy adults. They found that 220 minus age tends to underestimate maximum heart rate in older adults (Tanaka et al.). The five zones are fixed percentages: zone 1, 50 to 60 percent; zone 2, 60 to 70 percent; zone 3, 70 to 80 percent; zone 4, 80 to 90 percent; zone 5, 90 to 100 percent. These are training conventions, not clinical thresholds. Older adult guidelines recommend aerobic exercise at moderate and vigorous intensity but do not require one universal five zone scheme (American College of Sports Medicine). With a resting heart rate, the calculator also shows Karvonen ranges: target = resting + percentage x (maximum - resting).

How to read the result

Look first at the pair of maximum estimates, not a single number. The gap between them is a reminder that age formulas predict a group average, not your measured maximum. The Tanaka column is the better single choice for older adults. Zone 2, from 60 to 70 percent of the estimate, is the easy aerobic zone. It is a pace at which you can talk in full sentences but not sing. On the Tanaka estimate at age 60, zone 2 is about 100 to 116 bpm. If you add a resting heart rate, the Karvonen range will usually sit higher because it uses your own resting rate.

For a closer look at the easy zone, see zone 2 heart rate after 50. For the full set of age estimates, see maximum heart rate by age.

Why the formulas are estimates

Age explains much of the variation in maximum heart rate, but not all of it. In the HUNT Fitness Study, which measured maximum heart rate in 3,320 healthy adults, age alone predicted it with a standard error of 10.8 beats per minute (Nes et al.). Many people sit well above or below the age formula. Genes, training history, body size, medicines, and how hard you push all matter. A formula cannot tell you your true maximum, and a wrist device that estimates it from age inherits the same uncertainty. Adjust by effort and breathing rather than forcing the number. The talk test and a simple effort scale are useful checks.

Medicines and health conditions

Beta blockers lower heart rate during exercise, so age based zones can overestimate the heart rate you will reach at a given effort. In a study of 115 people recovering from a heart attack who were taking beta blockers, the standard Karvonen formula underestimated the heart rate at the anaerobic threshold (Tabet et al.). That does not mean you should change your formula or medicine. A heart rate target is less reliable when a medicine changes your heart rate response. Other medicines can also slow or speed the heart, including some calcium channel blockers, digoxin, ivabradine, and medicines for rhythm problems. Ask your doctor or cardiac rehabilitation team how to set intensity, and do not stop or change a medicine on your own.

Safety and doctor visits

Anyone with heart disease or symptoms should get clearance from a doctor before starting or increasing exercise. That includes people who have had a heart attack, stent, bypass, stroke, or heart failure, or who have a known rhythm problem. The same applies if you get chest pain, fainting, unusual breathlessness, or an irregular pulse with dizziness during activity. Your doctor may recommend an exercise test before you train at higher intensities. A test can measure your heart rate response and whether your rhythm or blood pressure changes abnormally with exercise. It is not needed for everyone.

Bring your age, resting heart rate, how you measured it, your medicines, and any heart or blood pressure conditions. List symptoms you have noticed during activity. Ask what warning signs should stop you and how to progress. If you also track blood pressure, the blood pressure checker can put a reading in context, and the guide to taking blood pressure at home explains technique. See normal blood pressure by age, how to read blood pressure, and pulse pressure. The hypertension stages guide explains the categories above the normal range.

Frequently asked questions

How accurate is the 220 minus age formula?

It is a rough population estimate. The Tanaka equation fits older adults better, and measured maximum heart rate varies around age formulas by about 11 beats per minute (Nes et al.). Treat both as starting points.

Should I use the 220 minus age or the Tanaka number?

Use the Tanaka number as the main estimate if you want one figure, because it was built with more older adults (Tanaka et al.). Keep 220 minus age for comparison.

What is a zone 2 heart rate?

Zone 2 is 60 to 70 percent of estimated maximum heart rate. On the Tanaka estimate at age 60, that is about 100 to 116 bpm. It is an easy pace at which you can talk in full sentences but not sing. The zone 2 guide explains how to find your own range by effort.

Why are my zones different from my watch?

A watch may use a different maximum heart rate formula, your resting heart rate, or its own algorithm. It may also use heart rate reserve rather than a percentage of maximum. None is a direct measurement of your true maximum, so small differences are expected.

Do beta blockers change heart rate zones?

Yes. Beta blockers lower heart rate during exercise, and a study in beta blocked patients found the standard Karvonen formula underestimated the heart rate at the anaerobic threshold (Tabet et al.). Ask your doctor or cardiac rehabilitation team how to set intensity, and do not change a medicine on your own.

Is zone 2 the fat burning zone?

Zone 2 is often called the fat burning zone. This calculator does not estimate fat burning, and the label is not a promise about weight or body fat. Use zone 2 as an easy pace you can sustain.

For a neutral comparison of supplement labels and the evidence behind them, see our heart and circulation supplements compared guide.