Maximum heart rate (MHR or HRmax) is the highest number of beats per minute your heart can achieve during maximum physical exertion. It is a fundamental physiological parameter used to personalise exercise intensity — all heart rate training zones are derived as percentages of your MHR.

Unlike resting heart rate, MHR does not improve with fitness. It is largely determined by age and genetics — it typically decreases by approximately one beat per minute per year after the age of 20. This is why all the common MHR formulas are based on age as the primary input.

The classic "220 minus age" formula is the most widely known but is also the least accurate for individuals over 50. The Tanaka formula (208 − 0.7 × age), developed from a meta-analysis of 351 studies, is the most validated general-population formula and is recommended for athletes and older adults. This calculator shows all four major formulas side-by-side and gives your five training zones based on your chosen result.