Heart Rate Zone Calculator

The standard formula uses a simple percentage of maximum heart rate (220 - age), while the Karvonen method uses heart rate reserve (max HR - resting HR) which accounts for individual fitness levels. The Karvonen method is more accurate, especially for trained athletes who typically have lower resting heart rates.

Age-predicted formulas have a standard deviation of ±10-12 bpm. For most people, these zones provide good training guidance. However, individual variation exists due to genetics, medications, and fitness level. For precise zones, consider lactate threshold testing with a sports scientist.

Zone 2 (60-70% max HR) is often called the 'fat burning zone' because it maximizes fat oxidation. However, higher intensity zones burn more total calories. For weight loss, combine Zone 2 base training (80% of training time) with some higher intensity work (20%) for optimal results.

Measure your resting heart rate first thing in the morning, before getting out of bed, for 3-5 consecutive days and take the average. Use your fingers on your wrist or neck, count for 60 seconds, or use a heart rate monitor. Normal resting heart rate ranges from 60-100 bpm for adults.

Yes, especially beta-blockers which can reduce maximum heart rate by 10-15 bpm. ACE inhibitors, calcium channel blockers, and some antidepressants can also affect heart rate. If you take medications that affect heart rate, consult your doctor before using these zones for training.

Recalculate every 3-6 months or when your fitness level significantly changes. As you get fitter, your resting heart rate may decrease, making the Karvonen method more accurate. Age-related changes in maximum heart rate are gradual (about 1 bpm per year after age 30).