Calculadora da Fórmula de Karvonen
- Created by
- Renato Passos, Eng. de Software
- Reviewed by
- Renato Passos, Eng. de Software
Last updated: Apr 18, 2026
Formula
alvo = (FCmax − FCrep) × % + FCrep
About this calculator
The Karvonen Formula Calculator determines the target heart rate for aerobic exercise by considering the individual's heart rate reserve. Unlike age-based methods, it uses resting heart rate (RHR) and maximum heart rate (MHR) to calculate personalized training zones. The formula is: Target HR = (MHR − RHR) × % intensity + RHR. The result indicates the ideal beats per minute to optimize fitness, whether for fat burning (50-70%) or cardiovascular training (70-85%).
To use the calculator, you need to input your MHR (can be estimated by 220 − age or measured in a test) and your RHR (measured upon waking, at rest). Then, choose the desired intensity percentage. This calculation is useful for athletes, runners, cyclists, swimmers, or any activity requiring heart rate control. It helps avoid workouts that are too light or too intense, preventing injuries and improving performance.
Important caveats: the formula assumes MHR and RHR are accurate. The age-estimated MHR may not be precise for highly trained individuals or those with heart conditions. For safety, consult a doctor before starting an exercise program, especially if you have a history of cardiovascular issues. Intensity should be adjusted based on perceived exertion and personal goals.
Common use cases include: runners training in the aerobic zone, cyclists monitoring effort on climbs, or people in cardiac rehabilitation (under medical supervision). It is also used by personal trainers to prescribe individualized workouts. Remember to reassess your RHR periodically, as it decreases with conditioning, altering target zones.
Frequently asked questions
What is the difference between the Karvonen Formula and the 220 minus age method?
The 220 minus age method gives a generic MHR without considering fitness level. Karvonen uses resting heart rate, adjusting the target zone for each person, resulting in more precise workouts.
Can I use the calculator if I take blood pressure medication?
Some medications affect heart rate. Consult your doctor to see if the formula is appropriate and what intensity limits are safe.
How do I correctly measure my resting heart rate?
Measure it right after waking, before getting out of bed, using a heart rate monitor or counting beats at your wrist for 60 seconds. Do this for a few days and take the average.
Does the formula work for any age?
Yes, but estimating MHR by age (220 − age) is less accurate for children and the elderly. For greater accuracy, prefer an exercise test with a professional.
What intensity should I use for weight loss?
For fat burning, an intensity between 50% and 70% of heart rate reserve is recommended. However, total calorie expenditure depends on exercise duration and type.