Count the number of large squares between two consecutive R waves and divide 300 by that number
Count the number of small squares between two consecutive R waves and divide 1500 by that number
Use the 6-second method by counting the number of QRS complexes in 6 seconds and multiplying by 10
Use the 10-second method by counting the number of QRS complexes in 10 seconds and multiplying by 6
For irregular rhythms, use the 6-second method
For regular rhythms, use the large-square or small-square method
Check the ECG paper speed before calculating the rate
At 25 mm/s, one large square equals 0.2 seconds and one small square equals 0.04 seconds
At 50 mm/s, one large square equals 0.1 seconds and one small square equals 0.02 seconds