The maximum heart rate formula for estimating exercise intensity is simple: subtract your age from 220. For example, a 30-year-old would have a maximum heart rate of 190 beats per minute (220 - 30 = 190). This estimation helps individuals determine their target heart rate while exercising, usually aimed at 50-85% of maximum heart rate for improving cardiovascular fitness. Monitoring heart rate during workouts can guide how hard one is training and ensure they remain within a safe and effective intensity level.