Fat-Burning Zone Calculator
Find the moderate heart-rate zone that maximizes fat oxidation.
Fat-burning zone (60–70% HRR)
136–148 bpm
Estimated max HR
185 bpm
Conversational check
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What 'fat-burning' really means
At moderate intensity the fuel mix leans hardest on fat — roughly 60–70% of heart-rate reserve, the zone where conversation stays easy. Higher intensities burn more total calories (and still plenty of fat); the zone's real virtue is that it's sustainable for long durations.
Zone 2 as a training base
Endurance coaching builds most weekly volume in this same easy zone: it grows mitochondria and fat-oxidation capacity while leaving you fresh for hard days. If most workouts feel like a race, the fat-burning zone is the correction.
Frequently asked questions
- How does the Fat-Burning Zone Calculator work?
- Find the moderate heart-rate zone that maximizes fat oxidation.
- Is the Fat-Burning Zone Calculator free to use?
- Yes. The Fat-Burning Zone Calculator is completely free, runs entirely in your browser, and requires no account or sign-up. Your inputs never leave your device.
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