Heart rate zone calculator
Find your training zones in beats per minute with the Karvonen formula. Enter your age; resting heart rate is optional and makes the result more precise.
How the Karvonen formula works
The calculation is target HR = (max HR − resting HR) × intensity + resting HR. The gap between max and resting heart rate is your heart rate reserve, and that is what intensity applies to — which is why the method tailors the zones to each person's fitness.
If you leave resting heart rate blank, we use the simple method (a direct percentage of max heart rate). For max heart rate, when no measured value is given, we estimate it with the Tanaka formula (208 − 0.7 × age), now more accepted than the classic 220 − age.
Want to understand each zone and how to build a running or cardio session from them? See the guide on the Karvonen formula and heart rate zones, and estimate the burn with the cardio calorie calculator.
Frequently asked questions
What is the Karvonen formula?
The Karvonen formula uses heart rate reserve (max heart rate minus resting heart rate) to find the target rate for each zone: target HR = (max HR − resting HR) × intensity + resting HR. Because it factors in resting heart rate, it personalizes the zones better than a plain percentage of max heart rate.
Which is the fat-burning zone?
It is Zone 2, between 60% and 70% intensity. There the body uses a higher proportion of fat as fuel, at a comfortable, long-duration pace. For total calorie burn, though, higher zones burn more calories per minute.
How do I find my maximum heart rate?
A supervised stress test is ideal. Without one, we estimate it with the Tanaka formula (208 − 0.7 × age), now more accepted than the classic 220 − age. If you already know your measured max heart rate, enter it in the matching field and we use that value.
Prescribe running and cardio by zones
Build running and cardio plans with intensity zones, spread them across the week and track your client's progress. 14-day free trial, no card.