ECG Heart Rate & R-R Interval Calculator

How to calculate Heart Rate from R-R?

The R-R interval represents the time between two consecutive R waves on an ECG. Heart rate is derived from this time gap.

Formula: HR (BPM) = 60,000 / R-R interval (ms)

Using the ECG calculator: an example

If an ECG strip shows a consistent R-R interval of 750ms, the calculation follows a simple ratio.

Step-by-step calculation:

• Identify the distance between R peaks (e.g., 750ms).
• Divide the total milliseconds in one minute (60,000) by the interval.
• The result (80 BPM) represents the heart rate.

Frequently Asked Questions

What is a normal R-R interval?

A normal R-R interval typically ranges between 600ms and 1000ms, corresponding to 60-100 BPM.

Why is the constant 60,000 used?

There are 60 seconds in a minute, and each second has 1,000 milliseconds, totaling 60,000ms per minute.

How does tachycardia affect the R-R interval?

As heart rate increases (tachycardia), the time between heartbeats decreases, resulting in a shorter R-R interval.