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: count the number of QRS complexes in 6 seconds and multiply by 10
Use the 10-second method: count the number of QRS complexes in 10 seconds and multiply by 6
For irregular rhythms, use the 6-second method
For regular rhythms, use the 300 rule or 1500 rule