Heart Rate Zones Calculator
Find your five cardio training zones based on your age. Optionally add resting heart rate for the Karvonen (heart rate reserve) method.
100% client-side · no upload
Max HR
How to use
- Enter your age. The calculator uses the formula Max HR = 220 − age.
- Optionally add your resting heart rate (measured first thing in the morning) to use the Karvonen method for more accurate zones.
- Click Calculate Zones to see your five training zones.
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- BMR Calculator — baseline calorie burn at rest
- Sleep Cycle Calculator — recovery sleep optimization
- Water Intake Calculator — hydration needs with exercise
よくある質問
- Is this heart rate zones calculator free?
- Yes, completely free with no signup and no usage limits.
- Does my data leave my device?
- No. All calculations run in JavaScript inside your browser. Nothing is sent to any server.
- Does it work on mobile?
- Yes. The calculator is mobile-first and works on iPhone Safari and Android Chrome.