Target Heart Rate Calculator
This free target heart rate calculator finds your exercise heart rate zones from your age and resting heart rate, using the Karvonen (heart rate reserve) method. Nothing you enter is sent anywhere or stored.
How to Use It
- Enter your age and your resting heart rate.
- Your estimated maximum heart rate and target heart rate zones update instantly.
- Use the Moderate zone for general fitness, or the Vigorous zone for a harder effort.
How It Works
Maximum heart rate is estimated as 220 minus your age. Heart rate reserve is the gap between that estimated maximum and your resting heart rate, the range your heart actually has available to work with during exercise. The Karvonen method applies your chosen exercise intensity to that reserve, then adds your resting heart rate back on top, rather than applying the intensity to your maximum heart rate alone.
Formulas
max heart rate = 220 − age
heart rate reserve = max heart rate − resting heart rate
target heart rate = (heart rate reserve × intensity %) + resting heart rate
A worked example: at age 30 with a resting heart rate of 65, estimated maximum heart rate is 190 and heart rate reserve is 125. A moderate 50% intensity target comes to 128 beats per minute, and a vigorous 85% intensity target comes to 171 beats per minute.
This is a general fitness estimate based on a common age based formula, not a personalized medical assessment. Everything runs client-side in your browser. Nothing you enter is sent anywhere or stored.
Frequently Asked Questions
What is the Karvonen method, and why does it use resting heart rate?
The Karvonen method calculates a target heart rate from your heart rate reserve, the gap between your estimated maximum heart rate and your resting heart rate, rather than simply taking a percentage of maximum heart rate alone. Two people can share the same age and the same estimated maximum heart rate but have very different fitness levels, which shows up in their resting heart rate. Including it gives a more personalized target than age alone would.
How do I measure my resting heart rate accurately?
The most accurate reading is taken first thing in the morning, before getting out of bed, using two fingers (not your thumb, which has its own pulse) on your wrist or neck, counting beats for a full 60 seconds, or 30 seconds doubled. Measuring after caffeine, exercise, or while stressed will read higher than your true resting rate.
Is "220 minus age" my actual maximum heart rate?
No, it is a widely used estimate, not a measurement of your specific maximum heart rate, which really can only be determined through a supervised maximal exercise test. Actual maximum heart rate varies from person to person even at the same age, sometimes by ten beats per minute or more. Treat the target zones here as a reasonable planning estimate, not an exact figure.
What is the difference between moderate and vigorous intensity exercise?
Moderate intensity (roughly 50 to 60% of heart rate reserve) is a pace where you can talk but not sing, commonly cited public health guidance for general cardiovascular benefit. Vigorous intensity (70% and above) is a harder effort where holding a conversation becomes difficult, associated with faster fitness gains but a higher demand on the body.
Is this safe for anyone to use?
This tool provides a general fitness estimate, not a personalized medical assessment. If you have a heart condition, are pregnant, or are new to exercise after a long period of inactivity, talk to a doctor before starting a new exercise intensity, especially anything in the vigorous range.