Target Heart Rate Calculator

This calculator finds your target heart rate zone for any exercise intensity level, from light warm-up to maximum effort. When a resting heart rate is provided, it uses the Karvonen formula (Heart Rate Reserve method), which accounts for your individual fitness level and produces a more personalized target than a generic formula. If resting heart rate is left at its default, a simple percentage of your estimated maximum heart rate (220 − age) is used instead. Both approaches are widely accepted in exercise science and used by coaches and fitness professionals. Use the light intensity zone (50–60%) for warm-ups and active recovery, the moderate zone (60–70%) for building aerobic endurance, the vigorous zone (70–80%) for improving cardiovascular fitness, and the hard or maximum zones for performance training and high-intensity interval work. A ±5 bpm range is displayed to reflect real-world variability in heart rate response during exercise. Training consistently within the correct zone ensures you achieve the intended physiological adaptation — whether that is fat burning, aerobic base building, or peak performance preparation.

Maximum Heart Rate (HRmax) = 220 − age. This is the widely used age-based estimate. If a resting heart rate is provided, the Karvonen (Heart Rate Reserve) method is used: Heart Rate Reserve (HRR) = HRmax − resting HR Target HR = (HRR × intensity %) + resting HR If no resting heart rate is provided, the simpler method is used: Target HR = HRmax × intensity % A ±5 bpm range is displayed to reflect real-world measurement variability. The Karvonen method is generally more accurate because it accounts for your individual cardiovascular fitness. A fitter person with a lower resting heart rate will have a larger Heart Rate Reserve, and the Karvonen formula assigns a proportionally higher absolute target heart rate at any given intensity level compared to a less fit person of the same age. This means two people of the same age training at 70% intensity may have meaningfully different target zones if their resting heart rates differ significantly.