Heart Rate Zones
Calculate your five cardio training heart rate zones from your age and resting heart rate.
100% client-side · no upload
Max Heart Rate
Zone 1 — Recovery
Zone 2 — Fat Burn
Zone 3 — Aerobic
Zone 4 — Threshold
Zone 5 — Max
How to use
- Enter your age. Max HR is calculated as 220 − age.
- Optionally enter your resting heart rate (measured first thing in the morning) to apply the Karvonen method for personalised zones.
- Results update instantly as you type.
Related tools
- Calorie Burn — Walking — calories burned by pace and duration
- BMR Calculator — baseline calorie burn at rest
- Sleep Cycle Calculator — recovery sleep optimisation
- Water Intake Calculator — hydration needs with exercise
More ways to use this tool
Frequently Asked Questions
- 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.
- What is the Karvonen method?
- The Karvonen formula uses your Heart Rate Reserve (HRR = Max HR − Resting HR) to personalise each zone relative to your individual fitness level rather than max HR alone. It gives more accurate training targets.
- How do I measure resting heart rate?
- Measure first thing in the morning before getting out of bed. Count your pulse for 60 seconds, or count for 30 seconds and multiply by 2. A healthy resting heart rate is 60–100 bpm; athletes often see 40–60 bpm.
Last updated: By jarvisbox