How Do You Calculate Heart Rate from an Ecg – Cost Calculator

ECG Heart Rate Calculator

This calculator helps you determine your heart rate directly from an electrocardiogram (ECG or EKG) tracing. Understanding how to calculate heart rate from an ECG is a fundamental skill in understanding cardiac rhythms and can be done using a few simple measurements from the ECG paper.

ECG Paper Speed (mm/sec): Commonly 25 mm/sec or 50 mm/sec.

Distance between R-waves (mm): Measure the distance between two consecutive R-waves in millimeters.

Result:

Your calculated heart rate will appear here.

How to Calculate Heart Rate from an ECG

The heart rate from an ECG can be calculated using the paper speed and the distance between two consecutive R-waves (the tallest peak in the QRS complex). The R-R interval represents one cardiac cycle.

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

This is the most precise method when the exact paper speed is known and you can accurately measure the R-R interval in millimeters.

Step 1: Determine Paper Speed: ECG machines typically run at a standard speed, most commonly 25 mm/sec. Sometimes, it might be set to 50 mm/sec. This information is usually printed at the top of the ECG tracing.
Step 2: Measure R-R Interval: On the ECG paper, measure the distance in millimeters between the peaks of two consecutive R-waves.
Step 3: Calculate Heart Rate: Use the following formula:
Heart Rate (bpm) = (Paper Speed in mm/sec * 60 sec/min) / (R-R Interval in mm)

Example Calculation:

Let's assume:

ECG Paper Speed = 25 mm/sec
Distance between R-waves = 20 mm

Using the formula:

Heart Rate = (25 mm/sec * 60 sec/min) / 20 mm

Heart Rate = 1500 / 20

Heart Rate = 75 bpm

Method 2: Using the "Large Boxes" Method (Approximation)

ECG paper is typically marked with small squares (1 mm) and larger squares (5 mm). If the paper speed is 25 mm/sec, then each large box represents 0.2 seconds (5 mm / 25 mm/sec = 0.2 sec).

Step 1: Count Large Boxes: Count the number of large boxes between two consecutive R-waves.
Step 2: Calculate Heart Rate:
Heart Rate (bpm) = 300 / (Number of large boxes between R-waves)

This method is an approximation and works best for regular rhythms.

Example Calculation (Large Boxes):

If there are approximately 4 large boxes between R-waves:

Heart Rate = 300 / 4