Target Heart Rate Zone Calculator
Calculate your target heart rate zones using the Karvonen (Heart Rate Reserve) method or the simple percentage method based on your age and resting heart rate.
Formulas
Maximum Heart Rate (Tanaka, 2001):
Max HR = 208 − 0.7 × Age
Karvonen Method (Heart Rate Reserve):
HRR = Max HR − Resting HR
Target HR = (Intensity% × HRR) + Resting HR
Simple Percentage Method:
Target HR = Intensity% × Max HR
Zones: Zone 1: 50–60% | Zone 2: 60–70% | Zone 3: 70–80% | Zone 4: 80–90% | Zone 5: 90–100%
Assumptions & References
- Max HR is estimated using the Tanaka formula (208 − 0.7 × age), which is more accurate than the older 220 − age formula, especially for older adults.
- The Karvonen method accounts for individual fitness level via resting heart rate and is generally considered more precise for training prescription.
- The simple percentage method uses only max HR and is a quick estimate suitable when resting HR is unavailable.
- Resting heart rate should be measured after at least 5 minutes of rest, ideally first thing in the morning.
- These zones are general guidelines. Consult a physician or certified trainer before starting a new exercise program.
- References: Tanaka H. et al. (2001), Journal of the American College of Cardiology; Karvonen MJ et al. (1957), Annals of Medicine and Experimental Biology; American Heart Association exercise guidelines.