Calculate Ecg Heart Rate Practice

ECG Heart Rate Calculator

An electrocardiogram (ECG or EKG) is a crucial diagnostic tool used to assess the electrical activity of the heart. One of the key pieces of information derived from an ECG is the heart rate, which can be calculated using the R-R intervals – the time between consecutive R waves on the QRS complex. This calculator helps you practice determining heart rate from an ECG strip.

Standard speed is 25 mm/sec

How to Calculate Heart Rate from an ECG

The heart rate can be calculated from an ECG strip using the R-R interval and the paper speed. The R-R interval is the distance between two consecutive R waves on the QRS complex, measured in millimeters (mm) on the ECG paper.

The standard speed for ECG paper is 25 mm/sec. Each small box on the ECG paper is typically 1 mm wide, and each large box (made up of 5 small boxes) is 5 mm wide.

Methods for Calculation:

1. Method 1: Using R-R Interval in Millimeters and Paper Speed

   This is the most direct method. First, determine the distance between two consecutive R waves in millimeters. Then, you need to know the speed at which the ECG paper is moving, usually in millimeters per second (mm/sec).

   The formula is:

   Heart Rate (bpm) = (ECG Paper Speed (mm/sec) / R-R Interval (mm)) * 60 (sec/min)

   Example: If the R-R interval is 15 mm and the ECG paper speed is 25 mm/sec, the heart rate is (25 mm/sec / 15 mm) * 60 sec/min = 1.67 * 60 = 100 bpm.

2. Method 2: Using the Number of Large Boxes between R-R Intervals

   A quicker, albeit less precise, method often used for approximating heart rate involves counting the large boxes between R waves.

   The formula is:

   Heart Rate (bpm) = 300 / Number of Large Boxes between R-R intervals

   Example: If there are 3 large boxes between two R waves, the heart rate is approximately 300 / 3 = 100 bpm.

   Note: This method assumes a standard paper speed of 25 mm/sec, where each large box represents 0.2 seconds (5 mm / 25 mm/sec).

This calculator uses the first, more precise method, allowing you to input the R-R interval in millimeters and the paper speed.