How to Calculate Heart Rate Zones
What is Heart Rate Zones?
Heart rate training zones define intensity levels for cardio exercise. The Karvonen formula uses heart rate reserve (HRmax − resting HR) to give personalised zones more accurate than simple %HRmax methods.
Step-by-Step Guide
- 1HRmax estimate = 220 − age (or use lab test)
- 2Heart rate reserve (HRR) = HRmax − Resting HR
- 3Zone HR = Resting HR + (HRR × % intensity)
- 45 zones: 50–60% / 60–70% / 70–80% / 80–90% / 90–100% HRR
Worked Examples
Input
Age 35 · Resting HR 60 · HRmax 185
Result
Zone 2 (aerobic base): 111–125 bpm
60+(185−60)×0.6 to 0.7
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