Heart Rate Zone Calculator

Heart rate zones are ranges of beats per minute that match different workout efforts. For a 30-year-old with a resting heart rate of 60, Zone 2 is 138 to 151 bpm. This calculator works out five zones for you with the Karvonen method.

The Karvonen method uses your heart rate reserve: your maximum heart rate minus your resting heart rate. The tool estimates your maximum as 220 minus your age. Each zone is a percentage of the reserve, added back onto your resting rate. For age 30 and a resting rate of 60, the reserve is 190 - 60 = 130. Zone 2 at 60% to 70% is then 60 + 78 to 60 + 91, or 138 to 151 bpm.

The five zones are Zone 1 recovery (50% to 60%), Zone 2 fat burn (60% to 70%), Zone 3 aerobic (70% to 80%), Zone 4 anaerobic (80% to 90%) and Zone 5 VO2 max (90% to 100%). Lower zones feel easy enough to talk in full sentences. Zone 4 and 5 efforts can only be held for short periods.

Because it includes your resting heart rate, this method adjusts to fitness. A fitter person with a lower resting rate gets a wider reserve. Measure your resting rate on waking, before you get up, over a few mornings, and use the average.

The weak spot is the 220-minus-age estimate. Real maximum heart rates vary a lot between people of the same age, so your zones may feel too hard or too easy. A supervised exercise test gives a truer maximum. Medicines such as beta blockers also change heart rate. If you have a heart condition or are starting to exercise after a long break, check with your doctor first. To plan runs by speed instead, use the Pace Calculator.