OptiDrop

Heart Rate Zone Calculator

Calculate your 5 heart rate training zones to optimize your workouts. Know exactly what intensity to train at for warm-up, fat burn, cardio, hard effort, and maximum performance.

For more accurate zones using the Karvonen formula

Related Tools

BMR & TDEE Calculator Calculate your daily calorie needs. BMI Calculator Calculate your Body Mass Index.

Understanding Heart Rate Training Zones

Heart rate training zones are ranges of heart rate intensity that correspond to different training effects. Training in the right zone helps you achieve specific fitness goals, whether that is building endurance, burning fat, improving speed, or increasing VO2 max.

How Maximum Heart Rate is Estimated

The most common formula is MHR = 220 - age. While simple, it provides a reasonable estimate for most people. Individual max HR can vary significantly based on genetics, fitness level, and other factors. For the most accurate number, a supervised maximal exercise test is recommended.

The Karvonen Formula

When you provide your resting heart rate, this calculator uses the Karvonen formula for more personalized zones: Target HR = ((Max HR - Resting HR) x Intensity%) + Resting HR. This method accounts for individual fitness levels, making it more accurate than simple percentage-based zones.

How to Use Your Zones

  • Zone 1 (50-60%): Easy warm-up and cool-down. Great for recovery days and beginners.
  • Zone 2 (60-70%): The "fat burning zone." Sustainable for long sessions. Builds aerobic base.
  • Zone 3 (70-80%): Aerobic training zone. Improves cardiovascular fitness and efficiency.
  • Zone 4 (80-90%): Anaerobic threshold. Improves speed and lactate tolerance.
  • Zone 5 (90-100%): Maximum effort. Short intervals only. Improves VO2 max and power.

A well-rounded training program typically spends about 80% of time in Zones 1-2 (easy training) and 20% in Zones 3-5 (hard training). This is known as polarized training and is used by elite endurance athletes worldwide.

Frequently Asked Questions

Maximum heart rate (MHR) is commonly estimated using the formula: MHR = 220 - age. This is a widely used estimation, though individual max HR can vary by 10-20 beats per minute. For a more accurate measurement, a supervised maximal exercise test is recommended.
Zone 1 (50-60% of max HR) is warm-up and recovery. Zone 2 (60-70%) is fat burning and easy pace. Zone 3 (70-80%) is aerobic/cardio fitness. Zone 4 (80-90%) is anaerobic threshold and hard effort. Zone 5 (90-100%) is maximum effort and VO2 max training.
Zone 2 (60-70% of max HR) is often called the fat-burning zone because a higher percentage of calories burned come from fat. However, higher intensity zones burn more total calories per minute. For overall fat loss, a combination of Zone 2 steady-state cardio and Zone 3-4 interval training is most effective.
Yes. When you provide your resting heart rate, the calculator uses the Karvonen formula: Target HR = ((Max HR - Resting HR) x %intensity) + Resting HR. This provides more personalized zones since fitter individuals have lower resting heart rates. Without it, the standard percentage-of-max-HR method is used.

Last updated: June 2026