Heart Rate Zone for Fat Loss Calculator
Calculate your ideal Target Heart Rate (THR) for maximum fat oxidation using the Karvonen formula.
Note: This calculation uses 60% – 70% of your Heart Rate Reserve (HRR) for the "Fat Burn" target.
Understanding the Fat Loss Heart Rate Zone
The "Fat Loss Zone" is a specific intensity range during exercise where your body burns a higher percentage of calories from stored fat rather than glycogen (carbohydrates). Scientifically, this typically occurs at moderate intensities.
While high-intensity interval training (HIIT) burns more total calories in a shorter time, exercising within your specific fat-burning heart rate zone allows for longer sessions with less recovery demand, making it ideal for base building and consistent weight management.
How This Calculator Works
This tool uses the Karvonen Formula, which is widely considered more accurate than the simple "220 minus age" method because it accounts for your cardiovascular fitness level by including your Resting Heart Rate (RHR).
- Step 1: Calculate Maximum Heart Rate (MHR = 220 – Age).
- Step 2: Determine Heart Rate Reserve (HRR = MHR – Resting HR).
- Step 3: Calculate intensity levels (Intensity % × HRR) + Resting HR.
Heart Rate Zone breakdown
| Zone | Intensity | Primary Benefit |
|---|---|---|
| Zone 1: Very Light | 50% – 60% | Recovery, warm-up, basic health. |
| Zone 2: Fat Burn | 60% – 70% | Highest percentage of fat utilization. |
| Zone 3: Aerobic | 70% – 80% | Cardiovascular endurance improvement. |
| Zone 4: Anaerobic | 80% – 90% | Improved speed and power. |
Example Calculation
Imagine a 30-year-old individual with a resting heart rate of 60 BPM:
- MHR: 220 – 30 = 190 BPM
- HRR: 190 – 60 = 130 BPM
- 60% Intensity: (130 × 0.60) + 60 = 138 BPM
- 70% Intensity: (130 × 0.70) + 60 = 151 BPM
In this example, the ideal fat-burning zone is between 138 and 151 beats per minute.
Frequently Asked Questions
Is the Fat Loss Zone a myth?
Not entirely. While you burn a higher *percentage* of fat in this zone, total calorie expenditure is higher in more intense zones. However, Zone 2 training (fat loss zone) is critical for metabolic health and mitochondrial efficiency.
When should I measure my Resting Heart Rate?
For the most accurate results, measure your heart rate immediately after waking up, while still in bed, using a fitness tracker or by counting pulses at your wrist for 60 seconds.
Can I burn fat outside this zone?
Yes. Fat loss ultimately depends on a caloric deficit. However, training in this zone helps preserve muscle mass and ensures you aren't overtraining, which can lead to injury or burnout.