Fat Burning Zone Calculator
Find your optimal fat-burning heart rate zone — the 60–70% max HR range where the body draws the highest proportion of energy from fat stores.
Reviewed October 7, 2026 Runs in your browser — inputs are never stored
This tool provides general sports and fitness estimates for educational purposes only. It is not medical advice — consult a physician before starting or intensifying training, especially if you have a cardiovascular condition.
About the Fat Burning Zone Calculator
The fat burning zone calculator finds the heart-rate range of 60–70% intensity, where fat supplies a larger share of the energy you burn. It uses the Karvonen method — a percentage of heart-rate reserve added to your resting rate — and also shows the simple percentage-of-maximum version. Total calories burned still matter most for weight loss.
How to use it
- 1Enter your age.
- 2Enter your resting heart rate, measured on waking.
- 3Press Calculate to see your zone in beats per minute.
Worked example
a 40-year-old with a resting heart rate of 65 has an estimated maximum of 180 bpm and a fat-burning zone of about 134–146 bpm.
How it works
Formula
Fat Burn Zone = (Max HR − Resting HR) × 60–70% + Resting HR (Karvonen). Simple: Max HR × 60–70%.
Common use cases
- Setting easy-cardio targets
- Setting heart-rate alerts on a watch
- Structuring walking or cycling sessions
Frequently asked questions
A:The fat burning zone is 60–70% of your maximum heart rate, where the body uses a higher percentage of fat for fuel.
A:Higher intensity burns more total calories, which may be more effective for overall fat loss. The zone burns a higher fat percentage, not necessarily more total fat.
A:A simple estimate is 220 − Age. More accurate formulas exist (Tanaka, Gulati).
A:Including resting HR in the Karvonen formula gives a more personalized zone based on heart rate reserve.
A:At least 30–60 minutes is recommended for fat-burning zone workouts to be effective.
Reviewed for accuracy · Last updated October 7, 2026
Formulas follow published sports-science literature and official league definitions (Karvonen heart rate reserve, Cooper and Bruce protocols, MET compendium values, and standard baseball, cricket, and basketball statistics).
CalcWisee Editorial Team
Calculator development and formula review
CalcWisee is an independent site founded by Ayman. Every calculator is built from a published formula or official definition, tested against hand-worked examples before it goes live, and corrected promptly when a reader reports an issue to ayman@calcwisee.com.
Expertise: Financial mathematics, Health and fitness formulas, Applied mathematics, Unit conversion standards
References & sources