Target Heart Rate Zones Calculator
Calculate your target heart rate zones for fat burning, cardio and peak training. Karvonen formula based. Free fitness tool.
Uses the Karvonen formula when a resting heart rate is given, otherwise the simpler 220-minus-age estimate.
Frequently asked questions
- What are heart rate zones?
- Ranges of beats per minute that correspond to training intensity, from easy warm-up to all-out effort.
- Which zone burns the most fat?
- Zone 2 uses the highest share of fat for fuel, but higher zones burn more total calories. A mix works best.
- Why does resting heart rate matter?
- It makes the zones personal. The Karvonen formula uses heart rate reserve, which fits trained and untrained people better than 220-age alone.
- How accurate is 220 minus age?
- It is a rough population average with a standard deviation of about 10 bpm. A lab test gives exact numbers.
This tool runs entirely in your browser. No data is uploaded anywhere.