What Is the Target Heart Rate Zone Calculator?
This calculator estimates the heart rate you should aim for during exercise at a chosen intensity. It first estimates your maximum heart rate (HRmax) from your age, then scales it by the percentage of effort you want to train at. Training within a target zone helps you exercise efficiently and safely, whether your goal is fat burning, endurance, or peak performance.
How to Use It
Enter your age in years and the intensity percentage you want to train at (typically between 50% and 85% for most workouts). The calculator returns your target heart rate in beats per minute, along with your estimated maximum heart rate.
The Formula Explained
The widely used age-predicted maximum heart rate is \(\text{HRmax} = 220 - \text{age}\). Your target heart rate for a given effort level is then:
$$\text{HR} = \left(220 - \text{age}\right) \times \frac{\text{intensity\%}}{100}$$For example, the 70% zone for a 40-year-old is calculated by first finding \(\text{HRmax} = 220 - 40 = 180\), then multiplying by \(0.70\).
Worked Example
A 40-year-old wants to train at 70% intensity. \(\text{HRmax} = 220 - 40 = 180\) bpm. $$\text{Target HR} = 180 \times \frac{70}{100} = 126 \text{ bpm}$$ They should aim to keep their heart rate around 126 bpm during the workout.
FAQ
How accurate is 220 − age? It is a simple population estimate and can be off by 10–20 bpm for any individual. For precise training, a measured maximum heart rate or lab test is better.
What intensity should I choose? Light activity is roughly 50–60%, moderate cardio 60–70%, aerobic/endurance 70–80%, and high-intensity 80–90% of maximum.
Is this medical advice? No. Consult a doctor before starting vigorous exercise, especially if you have a heart condition or take medications that affect heart rate.
