Heart Rate Zone Calculator
Know your max? Enter it. Otherwise, estimate using the button (220 - age).
Frequently Asked Questions
Heart rate zones are ranges of heart rate expressed as a percentage of your maximum heart rate. Each zone triggers different physiological adaptations — from fat burning (Zone 2) to cardiovascular improvement (Zone 3-4) to peak performance (Zone 5).
The Karvonen formula (also called Heart Rate Reserve method) is more accurate than simple percentage of max HR. It accounts for your resting heart rate: Target HR = ((Max HR - Resting HR) × % intensity) + Resting HR.
Zone 2 (60-70% max HR) burns the highest percentage of calories from fat. However, higher zones burn more total calories. For weight loss, a mix of Zone 2 (long, easy workouts) and Zone 4 (HIIT) is most effective.
The 220 - age formula is a rough estimate with a ±10-12 bpm margin. A more accurate method is a VO2 max test, or finding the highest heart rate you've achieved during a very hard workout. Many GPS watches now estimate it.