How do I calculate target heart rate? Enter your numbers above and the result updates instantly. For example: Age: 35 yrs · Resting heart rate: 65 bpm → Target zone (Karvonen 50–85%): 125–167 bpm.
Is this Target Heart Rate Calculator free? Yes — completely free with no sign-up or paywall. It runs entirely in your browser and keeps working offline; the numbers you enter never leave your device.
How accurate is it? It uses the standard published formula for target heart rate. Results are estimates for planning — not financial, tax, medical, engineering, or legal advice.