Exercise Heart Rate Monitor Calculator
Calculate your recommended heart rate zones for different exercise types based on your age.
Plan safe and effective workouts.
Exercise heart rate zones define intensity levels for cardiovascular training based on your maximum heart rate (MHR). Training in different zones produces different physiological adaptations — from fat burning and aerobic base building to peak performance and VO2 max improvement.
Maximum Heart Rate formula: MHR = 220 − Age (Haskell & Fox, 1971 — most widely used) MHR = 208 − (0.7 × Age) (Tanaka formula, 2001 — more accurate for older adults)
Heart Rate Reserve formula (Karvonen method — more personalized): HRR = MHR − Resting Heart Rate (RHR) Target HR = RHR + (HRR × Zone Percentage)
What each variable means:
- MHR (Maximum Heart Rate) — the highest heart rate your cardiovascular system can achieve. Genetically determined and declines with age.
- RHR (Resting Heart Rate) — your heart rate when fully at rest (measure after waking, before getting up). Healthy adults: 60–80 BPM; highly fit athletes: 40–60 BPM.
- HRR (Heart Rate Reserve) — the range between resting and maximum. The Karvonen method uses this to calculate more personalized training zones.
- Zone percentage — the fraction of MHR (or HRR) that defines each training zone.
Standard 5-zone training system:
| Zone | % of MHR | Perceived Effort | Benefit |
|---|---|---|---|
| Zone 1 — Recovery | 50–60% | Very easy | Active recovery, fat burning |
| Zone 2 — Aerobic Base | 60–70% | Easy/conversational | Endurance, fat oxidation |
| Zone 3 — Aerobic | 70–80% | Moderate | Aerobic capacity |
| Zone 4 — Threshold | 80–90% | Hard, limited speech | Lactate threshold, speed |
| Zone 5 — VO2 Max | 90–100% | Maximum effort | Peak power, VO2 max |
Worked example: A 35-year-old with resting HR of 62 BPM.
MHR = 220 − 35 = 185 BPM HRR = 185 − 62 = 123 BPM
Zone 2 target HR (Karvonen, 60–70%): Lower = 62 + (123 × 0.60) = 62 + 73.8 = 136 BPM Upper = 62 + (123 × 0.70) = 62 + 86.1 = 148 BPM
Zone 4 target (Karvonen, 80–90%): Lower = 62 + (123 × 0.80) = 160 BPM Upper = 62 + (123 × 0.90) = 173 BPM