Heart Rate Zone Calculator

Heart rate zones are ranges of heartbeats per minute that correspond to different exercise intensities. Zone 1 (50-60%) is for recovery, Zone 2 (60-70%) burns fat, Zone 3 (70-80%) improves aerobic fitness, Zone 4 (80-90%) builds speed, and Zone 5 (90-100%) is maximum effort.

The most common formula is 220 minus your age. For example, a 30-year-old has an estimated max HR of 190 bpm. More accurate methods include the Tanaka formula (208 - 0.7 × age) or a clinical stress test.

The Karvonen method uses your heart rate reserve (max HR minus resting HR) to calculate training zones. This method is more personalized than simple percentage of max HR, as it accounts for your fitness level.

Zone 2 (60-70% max HR) is traditionally called the 'fat burning zone' because a higher percentage of calories come from fat. However, higher intensity exercise burns more total calories, so both approaches are effective for weight loss.

Measure your resting heart rate first thing in the morning before getting out of bed. Use two fingers on your wrist or neck, count beats for 60 seconds. Take measurements for 3-5 consecutive days and calculate the average. A lower resting heart rate generally indicates better cardiovascular fitness.

Zone 2 training (60-70% max HR) builds aerobic base, improves fat metabolism, and increases mitochondrial density. Athletes spend 80% of training time in Zone 2 for endurance development. It feels 'easy' - you should be able to hold a conversation. This zone improves efficiency without excessive stress on the body.

Most training (70-80%) should be in Zones 1-2 for aerobic base. Zone 3 for 10-20% of weekly training to improve threshold. Zones 4-5 for only 5-10% in short, intense intervals. Beginners should focus almost entirely on Zones 1-2. Elite athletes strategically use all zones based on competition goals.

Heart rate fluctuates due to hydration status, temperature, caffeine, stress, sleep quality, illness, altitude, and accumulated fatigue. It can be 5-10 bpm higher in hot weather or when dehydrated. Don't obsess over daily variations - focus on trends over weeks and how you feel (perceived exertion).

Optical wrist-based heart rate monitors are generally 90-95% accurate during steady-state exercise but less reliable during high-intensity intervals or strength training. Chest strap heart rate monitors using ECG technology are more accurate (98-99%). For precise training, especially intervals, chest straps are recommended.