Target Heart Rate Calculator

The Target Heart Rate Calculator estimates training heart rate zones to guide cardio workouts. It uses the Karvonen Formula — which factors in your resting heart rate — to produce personalized zone numbers. Heart rate zones help you control training intensity for goals like fat burning, aerobic conditioning, threshold training, and peak power.

Many athletes and fitness enthusiasts use zones rather than perceived exertion alone because heart rate provides an objective metric of cardiovascular load. Zones are often defined by percentages of heart rate reserve (HRR) or maximum heart rate (HRmax). The Karvonen method calculates target heart rate as: Target = ((HRmax − HRrest) × intensity) + HRrest, which accounts for individual resting fitness level.

How to measure HR values

To use this calculator, estimate your maximum heart rate (commonly 220 − age or other validated formulas) and measure your resting heart rate — ideally first thing in the morning before getting out of bed. If you know your true HRmax from a recent test, use that value for the most accurate zones.

Training applications and safety

Different zones serve different goals: low zones build endurance and support fat oxidation, moderate zones improve aerobic capacity, and high-intensity zones develop anaerobic power and VO2 max. Always warm up and cool down, and avoid sustained exercise at maximal intensities without appropriate conditioning and medical clearance if needed.

This calculator is informational and runs in your browser. If you have cardiovascular disease, are pregnant, or have risk factors, consult a healthcare professional before starting a new exercise program or using heart rate zones for intense training.