How to Calculate a Tune's Beats Per Minute and Adjust Pitch
Part of the DJing For Dummies Cheat Sheet (UK Edition)
Beats per minute (BPMs) are a way to describe how fast your records are. The name gives it away; the BPM is the number of beats that occur in one minute. Count how many beats play in 30 seconds. If you counted the first beat when you started your watch, subtract 1, then double the result. If you didn’t count that first beat, simply double the figure. That’s your BPM.
When you try to beatmatch two different records, knowing the BPM of each tune helps you make an educated guess as to how much to adjust the pitch control (which is what you use to make your tunes’ bass beats play at the same speed).
If you don’t want to guess, and want to figure the amount to change the pitch control more precisely, use the following formula to work out how much an adjustment on the pitch control will change the original BPM:
(Original BPM x pitch change) / 100 = BPM change
For example, 130 BPM tune with a 5 per cent pitch increase would be:
(130 x 5) / 100 = 6.5 BPM