Heart Rate Zone Calculator
Estimate common training zones from age and resting heart rate.
This page is an editable estimator with realistic defaults so you can model your own situation in minutes.
Zones use heart rate reserve: target = resting heart rate + intensity x (maximum - resting).
Treat the result as a planning estimate and verify important numbers with the relevant official source before acting.
| Zone 1 | 125 bpm to 137 bpm | 50% to 60% HRR |
|---|---|---|
| Zone 2 | 137 bpm to 149 bpm | 60% to 70% HRR |
| Zone 3 | 149 bpm to 161 bpm | 70% to 80% HRR |
| Zone 4 | 161 bpm to 173 bpm | 80% to 90% HRR |
| Zone 5 | 173 bpm to 185 bpm | 90% to 100% HRR |
Assumptions
- Heart rate reserve zones are estimates.
- Medication, heat, stress, caffeine, and fitness level can affect heart rate.
How this calculator works
Formula used
Zones use heart rate reserve: target = resting heart rate + intensity x (maximum - resting).
Example calculation
Plug in your own numbers and the result updates instantly. Zones use heart rate reserve: target = resting heart rate + intensity x (maximum - resting).
Heart Rate Zone Calculator FAQ
Is this heart rate zone calculator medical advice?
No. It is an educational estimate only and should not be used to diagnose, treat, or make medical, nutrition, legal, or emergency decisions.
Why might my real result be different?
Age, sex, body composition, pregnancy, medications, medical conditions, training status, lab methods, and measurement accuracy can all change real-world results.
Should I check these results with a professional?
Yes. Confirm health, nutrition, fitness, kidney function, alcohol, or safety decisions with a qualified professional or official source.