Fat Burning Zone Calculator

Enter your age and optionally your resting heart rate to calculate your personal fat burning heart rate zone. Choose between the simple age-based method or the more precise Karvonen method to get your target heart rate range — the zone where your body burns the most fat during exercise.

Disclaimer: This tool is for informational and educational purposes only. It is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before making any health-related decisions.

years

Your current age in years

bpm

Measure your pulse after resting for 10 minutes. Used for the Karvonen method.

The Karvonen method uses your resting heart rate for a more personalized result.

Results

Fat Burning Zone

--

Maximum Heart Rate (MHR)

--

Fat Burn Zone — Lower Bound (60%)

--

Fat Burn Zone — Upper Bound (70%)

--

Cardio Zone — Lower Bound (70%)

--

Cardio Zone — Upper Bound (85%)

--

Results Table

More Health & Fitness Tools

Frequently Asked Questions

How do I calculate my fat burning zone?

Your fat burning zone is typically 60–70% of your maximum heart rate (MHR). First, estimate your MHR using the formula MHR = 220 − age. Then multiply by 0.60 and 0.70 to get the lower and upper bounds of your fat burning zone. For example, a 35-year-old has an MHR of 185 bpm, giving a fat burning zone of 111–130 bpm.

How do I calculate maximum heart rate?

The most common formula is MHR = 220 − age. So a 30-year-old would have an estimated MHR of 190 bpm. This is a general estimate; actual MHR can vary based on fitness level, genetics, and health conditions. For a more accurate measurement, a supervised stress test can be performed.

What is my fat-burning zone?

Your fat-burning zone is the heart rate range at which your body burns the highest proportion of calories from fat — typically 60–70% of your maximum heart rate. Working out in this zone for sustained periods encourages the body to use stored fat as its primary fuel source rather than carbohydrates.

What heart rate is zone 2?

Zone 2 corresponds to approximately 60–70% of your maximum heart rate, which overlaps closely with the fat burning zone. It is a low-to-moderate intensity level where you can maintain a conversation while exercising. Zone 2 training is widely recommended for endurance building and fat oxidation.

How do I calculate my target heart rate using the Karvonen method?

The Karvonen method uses your Heart Rate Reserve (HRR), calculated as MHR − Resting Heart Rate (RHR). Your Target Heart Rate (THR) = (HRR × % intensity) + RHR. For fat burning at 60–70% intensity: THR_lower = (HRR × 0.60) + RHR and THR_upper = (HRR × 0.70) + RHR. This method gives a more personalized result than the age-based approach.

Is the fat burning zone the best zone for weight loss?

The fat burning zone maximizes the percentage of calories burned from fat, but higher-intensity zones burn more total calories overall. For long-term weight loss, a combination of fat-burning zone workouts (for endurance and fat oxidation) and higher-intensity cardio sessions tends to be most effective.

How accurate is the 220 − age formula?

The 220 − age formula is a widely used estimate but has a standard deviation of about ±10–12 bpm, meaning your actual MHR could be significantly higher or lower. It is best used as a practical starting point. For greater accuracy, the Karvonen method incorporating your resting heart rate provides a more individualized target.

How long should I exercise in the fat burning zone?

Most fitness experts recommend staying in the fat burning zone for at least 30–60 minutes per session to maximize fat oxidation. Since the intensity is relatively low, longer sessions are sustainable for most healthy adults. Aim for 3–5 sessions per week for best results.