This Zone 2 heart rate calculator finds the heart rate range for easy, steady aerobic training. Enter your age, and add your resting heart rate for a more personal result with the Karvonen method.
What is Zone 2 training?
Zone 2 is a low-to-moderate intensity where you can breathe steadily and still hold a conversation. Endurance athletes spend much of their training time here because it builds aerobic fitness while being easy enough to recover from quickly, and it is a popular way for beginners to exercise more without burning out.
Two ways to calculate Zone 2
Percentage of maximum heart rate: Zone 2 is about 60–70% of your maximum heart rate. If you don’t know your maximum, the calculator estimates it as 220 minus your age.
Heart rate reserve (Karvonen): Zone 2 = resting heart rate + 60–70% × (maximum heart rate − resting heart rate). Because it uses your resting heart rate, it adjusts for your current fitness, and fitter people get a slightly higher range.
Worked example
A 35-year-old has an estimated maximum heart rate of 185 bpm. By percentage of maximum, Zone 2 is 111–130 bpm. With a resting heart rate of 60 bpm, the heart rate reserve is 125, so the Karvonen Zone 2 range is 135–148 bpm.
Frequently asked questions
Why do the two methods give different ranges?
The percentage-of-max method ignores resting heart rate, while Karvonen includes it. Neither is perfect. Use the range as a guide and check it with the talk test: in Zone 2 you should be able to speak in full sentences.
How accurate is 220 minus age?
It is a population average, and individuals can differ by 10 bpm or more. If you know your real maximum from a supervised test, enter it for a better result.
How much Zone 2 should I do?
Public health guidelines, including the WHO’s, recommend 150–300 minutes of moderate activity per week for adults, and Zone 2 sessions count toward that.
Talk to a doctor before starting a new exercise plan if you have a heart condition or take medication that affects heart rate.