Heart Rate Training Zone Calculator

Zone 1 (50-60% MHR) is recovery, Zone 2 (60-70%) builds aerobic base, Zone 3 (70-80%) is tempo/endurance, Zone 4 (80-90%) is anaerobic threshold, and Zone 5 (90-100%) is VO2 max for peak performance.

The Karvonen formula calculates target heart rate using heart rate reserve: Target HR = (HR Reserve x Intensity%) + Resting HR. It is more personalized than simple percentage of max HR because it accounts for your fitness level via resting heart rate.

Zone 2 (60-70% of max HR) is often called the fat-burning zone because a higher percentage of calories come from fat. However, higher-intensity zones burn more total calories, which can be more effective for overall fat loss.