Target Heart Rate Calculator

How to use the target heart rate calculator

Enter your age and a resting heart rate measured in beats per minute while calm and awake. The calculator estimates maximum heart rate, heart-rate reserve, and five exercise-intensity ranges.

These ranges are planning estimates for adults, not required targets. Beginners may need to stay at lower effort, while trained athletes may use individualized zones derived from supervised testing.

Formula and zone method

Estimated maximum heart rate uses the Tanaka equation: 208 minus 0.7 times age. Heart-rate reserve is that estimate minus resting heart rate. The Karvonen method calculates a target as resting heart rate plus a chosen percentage of heart-rate reserve.

The five displayed bands run from 50% through 100% of reserve. Values are rounded to whole beats per minute, so neighboring bands share a displayed boundary.

The bands are labeled neutrally as Zone 1 through Zone 5, and each is shown with the percentage of reserve it covers. They are deliberately not named for an exertion such as light or hard: a percentage of heart-rate reserve does not, on its own, establish how an effort will feel to a particular person, and this calculator knows only an age and a resting heart rate. The numbering carries the one thing that is supported, which is the order.

Safety and limitations

Age formulas describe population averages and can differ considerably from an individual’s measured maximum. The spread is large enough to matter: a person’s true maximum commonly sits ten to twenty beats per minute away from the age estimate, which is about the width of one displayed band. Treat the whole table as approximate rather than the top or bottom of any single band as a threshold.

The percentages here are shares of heart-rate reserve, not of maximum heart rate. The same percentage of reserve is a harder effort than the same percentage of maximum, so a zone number should not be read as a named intensity borrowed from elsewhere. Use perceived effort and the ability to hold a conversation as a cross-check.

The highest band reaches the estimated maximum heart rate. It is used briefly, by trained people, usually under supervision, and it is not a target for general fitness or for anyone starting out.

Wrist-based optical sensors are least reliable exactly where these numbers matter most, at high heart rates and during hard efforts; a chest strap is generally more accurate. Heat, dehydration, elevation, illness, stress, caffeine, and medication can also change heart rate.

This calculator is not medical advice. Beta blockers and other medicines that act on heart rate lower both resting and maximum values, which makes these estimates invalid. Ask a healthcare professional before starting or changing exercise if you have a cardiovascular condition, symptoms, significant risk factors, are pregnant, or take medicine that affects heart rate. Stop exercising and seek urgent help for chest pain, fainting, severe shortness of breath, or other concerning symptoms, whatever the numbers say.