Target Heart Rate Calculator

The Karvonen method calculates target heart rate as a percentage of heart rate reserve (HRR), where HRR = maximum heart rate minus resting heart rate. The formula is: Target HR = (HRR * intensity%) + resting HR. This is more personalised than calculating a simple percentage of maximum heart rate because it accounts for your individual fitness level as reflected in your resting heart rate.

Measure your resting heart rate first thing in the morning before getting out of bed or engaging in any activity. Count your pulse for a full 60 seconds. For greatest accuracy, take measurements on three consecutive mornings and average the results. A heart rate monitor worn overnight can also give a reliable reading. Typical adult resting heart rate is 60 to 100 bpm; athletes often measure 40 to 60 bpm.

For general cardiovascular health, the American Heart Association recommends moderate-intensity exercise at 50 to 70% of maximum heart rate (or the equivalent Karvonen zones). For improving fitness and losing weight, 70 to 85% (moderate to vigorous) is more effective. Elite performance training incorporates all zones, with significant time in zone 2 (60-70%) for base building.

Two people with the same age (and thus the same estimated HRmax) but different resting heart rates have different cardiovascular fitness levels. A person with a resting HR of 50 bpm has a much larger heart rate reserve than one with 80 bpm. The Karvonen method uses this reserve, so the same 70% Karvonen intensity corresponds to the same relative physiological demand for both people.

The American Heart Association defines moderate-intensity physical activity as exercise that raises your heart rate to 50 to 70% of your maximum heart rate. Vigorous intensity is 70 to 85% of maximum heart rate. These percentages are based on the simple max HR method, not the Karvonen method. Equivalent Karvonen percentages are somewhat lower because of the resting HR adjustment.