Heart Rate Zone Calculator

How It Works

Heart rate training zones divide your effort into five levels based on your maximum heart rate. Zone 1 (50-60%) is active recovery — easy walking. Zone 2 (60-70%) is the aerobic or fat-burning zone where you build endurance and burn the highest percentage of fat. Zone 3 (70-80%) is tempo training that improves aerobic capacity. Zone 4 (80-90%) is the lactate threshold zone where you build speed endurance. Zone 5 (90-100%) is maximum effort for short intervals. The Karvonen method (using heart rate reserve) is more personalized because it accounts for your resting heart rate, which reflects your fitness level. A fitter person with a lower resting heart rate will have different absolute zone values than a beginner at the same age. Most endurance coaches recommend spending 80% of training time in Zones 1-2 and only 20% in Zones 3-5.