Target Heart Rate Calculator

Target heart rate varies by age because maximum heart rate decreases as you get older. For moderate exercise (50-70% intensity), a 20-year-old should aim for 100-140 bpm, a 40-year-old for 90-126 bpm, and a 60-year-old for 80-112 bpm. For vigorous exercise (70-85% intensity), these ranges increase to 140-170 bpm, 126-153 bpm, and 112-136 bpm respectively. Calculate your specific target using the formula: (220 - age) × desired intensity percentage.

The 220-minus-age formula provides a reasonable estimate for most people but can be inaccurate, especially for older adults. Research shows it may underestimate maximum heart rate by up to 40 beats per minute in seniors. Alternative formulas like Tanaka (208 - 0.7 × age) or Gulati (206 - 0.88 × age for women) often provide better accuracy. For precise maximum heart rate, consider a supervised stress test with medical professionals, though the 220-age formula works fine for general fitness purposes.

Exercising at 100% maximum heart rate is generally safe for healthy individuals during brief intervals, but it's unsustainable and unnecessary for most fitness goals. Professional athletes use this intensity for sprint training, typically for 30 seconds to 2 minutes at most. Most people should stay below 85% of maximum heart rate for regular workouts. Reaching your actual maximum heart rate requires extreme effort and is rarely beneficial—you gain more fitness improvements training at 70-85% intensity for longer periods.

The fat-burning zone (60-70% of maximum heart rate) uses fat as the primary fuel source, but higher-intensity zones burn more total calories, including fat calories. A common misconception suggests exercising in the fat-burning zone is best for weight loss, but you'll actually burn more fat overall by working at higher intensities (70-85% max HR) because you burn more calories per minute. For weight loss, total caloric expenditure matters more than which fuel source your body uses during exercise. The best approach combines both moderate-intensity, longer-duration workouts and higher-intensity interval training.

For healthy adults, consistently exceeding 85% of maximum heart rate during regular workouts is considered too high and increases injury risk without additional benefits. During intense exercise, briefly reaching 90-100% is acceptable, but this should represent a small portion of your workout time. A heart rate above 220 bpm is dangerous for most people. Warning signs your heart rate is too high include chest pain, excessive dizziness, nausea, severe breathlessness that doesn't improve with rest, or feeling faint. If you experience these symptoms, stop exercising immediately and seek medical attention if they persist.

Caffeine can increase your resting heart rate by 3-11 beats per minute and may slightly elevate your exercise heart rate, though the effect varies significantly between individuals. Regular caffeine consumers often develop tolerance, experiencing minimal heart rate changes. Research shows caffeine doesn't typically prevent you from reaching target heart rate zones during exercise, but it may make achieving those zones feel easier by reducing perceived exertion. If you're sensitive to caffeine, consider exercising before consuming it or reduce intake if your heart rate seems unusually elevated during workouts.

The 220-minus-age formula comes from observational data showing maximum heart rate naturally declines with age. While the exact origin is debated, the formula was popularized in the 1970s after researchers observed that maximum heart rate decreases by roughly one beat per year after age 20. This happens because the heart's electrical conduction system becomes less responsive over time, and the heart muscle becomes slightly less elastic. The number 220 represents the approximate maximum heart rate of a newborn or very young child, with subsequent decreases reflecting the aging cardiovascular system.

For weight loss, combining Zone 2 (60-70% max HR) for longer, steady sessions with Zone 3-4 (70-85% max HR) for shorter, intense workouts produces the best results. Zone 2 training improves your body's ability to burn fat as fuel and can be sustained for 45-90 minutes, burning significant total calories. Higher zones burn more calories per minute and create an "afterburn effect" where your metabolism stays elevated post-workout. A balanced weekly plan might include 2-3 Zone 2 sessions of 45-60 minutes and 1-2 Zone 3-4 sessions of 20-30 minutes, combined with a caloric deficit through diet for optimal fat loss.

Exercising consistently below 50% of maximum heart rate provides minimal cardiovascular benefits and won't significantly improve fitness or burn substantial calories. However, very light activity (40-50% max HR) still offers health benefits compared to being sedentary, including improved mood, reduced stress, and better circulation. If you're new to exercise or recovering from illness, starting at lower intensities makes sense. As fitness improves, gradually increase intensity to reach target zones. A persistently low heart rate during what should be moderate exercise might indicate excellent cardiovascular fitness (good) or a medical condition affecting heart rate (requires evaluation).

The optimal duration in your target heart rate zone depends on intensity and fitness goals. For fat burning (Zone 2, 60-70% max HR), aim for 30-60 minutes per session, 3-5 times weekly. For cardiovascular improvement (Zone 3, 70-80% max HR), 20-40 minutes per session, 2-4 times weekly suffices. For high-intensity training (Zone 4-5, 80-100% max HR), limit work intervals to 30 seconds to 5 minutes with recovery periods between, totaling 15-25 minutes including warm-up and cooldown. Beginners should start with shorter durations and gradually increase as fitness improves. Quality matters more than quantity—30 focused minutes at proper intensity beats 60 minutes of unfocused effort.