How is the regular rate of heartbeats calculated?

The calculation of the regular rate of heartbeats is determined by using the formula of dividing 1500 by the number of small boxes between R-R intervals on an ECG strip. This method is based on the standard ECG paper, which is marked in small boxes that represent fractions of seconds. Since each small box corresponds to 0.04 seconds, there are 1500 small boxes in one minute (60 seconds / 0.04 seconds per box = 1500 boxes).

When you measure the distance between consecutive R waves (the R-R interval), counting the number of small boxes involved gives you a representation of the time between heartbeats. By dividing 1500 by this number, you yield the heart rate in beats per minute (BPM). This is a widely used method for calculating the heart rate when the rhythm is regular, making it a straightforward approach for clinicians when assessing cardiac function.