*Calculated using the Karvonen Formula (HRR) for higher accuracy based on your resting heart rate.
What is the Fat Burning Zone?
The fat burning zone is a heart rate range where your body primarily uses stored fat for fuel instead of carbohydrates. While high-intensity exercise burns more total calories, exercising at 60% to 70% of your maximum heart rate ensures that a higher percentage of those calories come from fat deposits.
How We Calculate Your Zone
Our calculator uses two primary methods:
The Fox Formula: The standard 220 minus your age to find Maximum Heart Rate (MHR).
The Karvonen Formula: If you provide your resting heart rate, we calculate your Heart Rate Reserve (HRR). This is considered more accurate for athletes and individuals with specific fitness levels.
Heart Rate Zone Guide
Zone
Intensity
Benefit
Warm Up
50-60%
Recovery, heart health
Fat Burn
60-70%
Weight loss, endurance
Aerobic
70-80%
Cardiovascular fitness
Anaerobic
80-90%
Speed, performance power
Example Calculation
For a 40-year-old with a resting heart rate of 70 BPM:
Max HR: 220 – 40 = 180 BPM.
Fat Burning Low (Simple): 180 x 0.60 = 108 BPM.
Fat Burning High (Simple): 180 x 0.70 = 126 BPM.
Using the Karvonen method (more accurate), the range for the same individual would be roughly 136-147 BPM, as it accounts for their specific fitness baseline.