Heart-rate zones calculator
Estimate Zone 1–5 from age and sex (max HR), with optional resting HR for Karvonen.
—
— max bpm
Zone guide
| Zone | % max (simple) | Feel |
|---|---|---|
| 1 | 50–60% | Very easy recovery |
| 2 | 60–70% | Easy aerobic / base |
| 3 | 70–80% | Tempo / steady hard |
| 4 | 80–90% | Threshold |
| 5 | 90–100% | Max intervals |
Max HR uses 220 − age (male) or Gulati 206 − 0.88×age (female). Optional resting HR switches zones to Karvonen (heart-rate reserve).
Educational tool only — stop if you feel chest pain, dizziness, or unusual shortness of breath.