Heart Rate Zones Calculator
Calculate your target heart rate zones for different exercise intensities using the Karvonen formula. Know exactly when you are burning fat vs. building endurance.
How heart rate zones work
Karvonen method: zone% × (max-HR − resting-HR) + resting-HR. Max HR: 208 − 0.7×age (better than 220-age). Five zones: Warm-up 50-60%, Fat burn 60-70%, Cardio 70-80%, Threshold 80-90%, Max 90-100%.
Frequently asked questions
How accurate are the results?
Formulas used here are validated in population studies but cannot account for individual genetics, body composition, or medical conditions. Treat results as a starting point, not a medical diagnosis.
Should I consult a professional?
If you have specific health concerns, existing conditions, or are planning significant lifestyle changes, consult a qualified healthcare provider (doctor, dietitian, physiologist).
How often should I recalculate?
Recalculate when your weight changes more than 5%, activity level shifts significantly, or every 3-6 months for routine monitoring. Results are snapshots — your body changes daily.
About the Heart Rate Zones
Free heart rate zones calculator using the Karvonen method. Enter your age and resting heart rate to find your fat burn, cardio, and peak training zones. The tool runs entirely in your browser, so nothing you enter is uploaded or stored.
How to use the Heart Rate Zones
- Age (years) — your age in years.
- Resting heart rate (bpm) — your resting heart rate in bpm.
Last updated
For general wellness information only, not medical advice — see our disclaimer.