Heart Rate Calculator

The Inbar formula (205.8 - 0.685 × age) has shown to be the most accurate with an error margin of ±6.4 bpm. The Wohlfart formula is also highly accurate with gender-specific calculations, showing errors of ±6.5% for men and ±5.5% for women. The commonly used Fox formula (220 - age) has a larger error margin of ±12-15 bpm but is easy to calculate mentally.

To measure your resting heart rate accurately: 1) Take it first thing in the morning before getting out of bed, 2) Measure for a full 60 seconds or count for 30 seconds and multiply by 2, 3) Take readings for several days to establish a baseline, 4) Measure while sitting or lying quietly, and 5) Avoid measuring after consuming caffeine or during stress. A normal resting heart rate for adults ranges from 60-100 beats per minute.

Maximum heart rate naturally decreases with age due to several physiological changes: 1) Decreased responsiveness to adrenaline, 2) Reduced elasticity of heart tissue, 3) Changes in electrical conduction, and 4) Decreased maximal cardiac output. Research shows maximum heart rate typically decreases by about 0.7 beats per minute per year. However, regular exercise can help maintain cardiovascular efficiency even as maximum heart rate declines.

Zone 2 (60-70% of maximum heart rate) is typically considered optimal for fat burning. At this intensity, your body primarily uses fat as its fuel source. However, total calorie burn increases at higher intensities, even though the percentage of fat calories burned decreases. For optimal fat loss, combine Zone 2 training with higher intensity intervals and proper nutrition.