Identify the QRS complexes on the ECG strip
Count the number of large boxes between two consecutive R waves
Use the 300 rule: heart rate = 300 divided by the number of large boxes between R waves
Use the 1500 rule: heart rate = 1500 divided by the number of small boxes between R waves
For a 6-second strip, count the number of QRS complexes and multiply by 10
For irregular rhythms, count QRS complexes over 10 seconds and multiply by 6
If the rhythm is regular, use the R-R interval method
If the rhythm is irregular, use the 6-second method
Compare the calculated rate with the ECG paper speed
Verify the rate by checking multiple R-R intervals if needed