When you are interpreting an EKG, you must know how to count the heart rate. When you count the heart rate you are counting the ventricular and atrial rate. In this article, I am going to tell you how to count a heart rate using the six (6) second rule.

There are many ways you can count a heart rate on an EKG, but I find the six second rule to be the easiest and fastest way. In addition, the six second rule is great for counting heart rhythms that aren’t regular like, atrial fibrillation, atrial flutter, sinus arrhythmia, sinus rhythm with PVCs etc.

Before you can understand how to count the heart rate using the 6 second rule, you must first be familiar with the squares found on the EKG paper. These squares are found on the background, behind the rhythm. These squares can be hard to see at time, so if you don’t have the best vision, you may need a small magnifying glass. Each square and block represents a fraction of time.

## Video on How to Count Heart Rate with 6 Second Rule

Here is a diagram to illustrate what I’m talking about:

Important things to note about the squares:

- Each large block contains 25 squares
- Each small square represents 0.04 seconds of time
- 5 small squares equal 0.20 seconds of time
- When you are trying to calculate the heart rate with the six second rule, you must count out enough LARGE squares to equal 6 seconds. Therefore,
**30 large squares would equal 6 seconds.**

# How to Count Atrial and Ventricular Rate using the 6 Second Rule

**Atrial Rate**

- Identify the p-waves
- Beginning at the first p-wave start counting 30 large squares.
- Then count how many p-waves are between the 30 large squares.
- Take that number and multiple it by 10 and this is your heart rate.

**Ventricular Rate**

- Identify the r-waves
- Beginning at the first r-wave start counting 30 large squares.
- Then count how many r-waves are between the 30 large squares.
- Take that number and multiple it by 10 and this is your heart rate.

Quick Heart Rate Quiz

Answer: **Heart rate: 50 (sinus bradycardia)**

Answer: **Heart Rate: 120s (sinus tachycardia)**

Answer: **Heart Rate: 80s (atrial fibrillation)**