Target Heart Rate Calculator
Find your training heart rate zones with the Karvonen formula using your age and resting pulse.
This runs entirely in your browser. Your numbers are never uploaded.
How to use this tool
Enter your age in years and your resting heart rate in beats per minute, then select Calculate zones. The calculator estimates your maximum heart rate, your heart rate reserve, and a full set of training heart rate zones from 50 to 85 percent intensity. To find your resting heart rate, count your pulse for one full minute first thing in the morning before you get out of bed. Use Copy results to save the full breakdown for your training log.
The Karvonen formula and how it works
This target heart rate calculator uses the Karvonen method, which is more personal than a flat percentage of maximum heart rate because it factors in your resting pulse. The steps are:
Heart Rate Reserve (HRR) = HRmax - resting heart rate
Target heart rate = (HRR x intensity) + resting heart rate
The 50 to 60 percent band is the lighter fat burn zone, where a larger share of energy comes from fat and the effort feels easy. The 60 to 70 percent band builds aerobic base and endurance. The 70 to 80 percent band is the cardio or tempo zone, and the 80 to 85 percent band pushes toward your performance peak. These max heart rate zones give you simple targets to keep each workout in the right effort range.
A real example
Take a 40 year old with a resting heart rate of 60 bpm. First, HRmax = 220 - 40 = 180 bpm. Heart rate reserve = 180 - 60 = 120 bpm. For the 70 percent target: (120 x 0.70) + 60 = 84 + 60 = 144 bpm. For the 50 percent lower edge of the fat burn zone: (120 x 0.50) + 60 = 120 bpm. So a steady cardio session for this person sits around 144 bpm, while an easy fat-burning walk stays closer to 120 bpm.
Common questions
What makes this a Karvonen target heart rate calculator?
It uses your heart rate reserve, which is your maximum heart rate minus your resting heart rate, instead of just a percentage of your maximum. Because resting pulse varies from person to person, the Karvonen method gives a more individualized training heart rate than the simple percentage method.
Which is the fat burn zone?
The lower intensity bands, roughly 50 to 65 percent of your heart rate reserve, are commonly called the fat burn zone. At this easier effort a higher proportion of calories burned comes from fat, though higher intensity work still burns more total calories per minute.
How accurate is the 220 minus age maximum?
The 220 minus age formula is a quick population estimate and can be off by 10 to 12 beats per minute for any individual. A monitored treadmill or field test gives a truer maximum. Use these zones as a helpful guide, not an exact prescription.
How do I measure my resting heart rate?
Count your pulse for a full minute right after you wake up, before standing or drinking coffee. A fitness watch can also report it. A typical adult resting heart rate falls between 60 and 100 bpm, and trained athletes are often lower.
Is this medical advice?
No. This calculator is an estimate for general fitness and educational use only. It is not medical advice. If you have a heart condition, take medication that affects your pulse, or are starting a new exercise program, talk to a doctor first.