Calculate Samples per Beat

General

• the Duration of 1 Beat is 60/BPM Seconds

• the Number of Samples per Second is Defined by the Sample Rate (SR)

• so the Math to Calculate the Number of Samples per Beat is 60/BPM x SR

Example 1

• Tempo is 120 BPM and SR is 44100

1) Since 1 Beat is 60, we need to Divide 60 / 120

• 60 / 120 = 0.5

2) Since SR is 44100 we Need to Multiply that 0.5 by 44100

– 44100 x 0.5 = 22050 Samples per Beat

Example 2

• Tempo is 103 BPM and SR is 44100

1) Since 1 Beat is 60, we need to Divide 60 / 103 

• 60 / 103 = 0.5825242718

2) Since SR is 44100 we Need to Multiply that 00.5825242718 by 44100

• 44100 x 0.5825242718 = 25689.3203883495 Samples per Beat

Example 3 Reversed Technique

• Say you have a Loop with a Certain Number of Samples and you Want to Know What BPM it is

1) Given Number of Samples is 67632 and SR is 44100

– i.e. You Always Need to  Look at the Length of the “Forward Loop” and Divide the 2 Numbers, e.g. Above Picture 135265 – 67632 = 67633

2) So the Math to Calculate the Respective BPM is 60/Samples x SR x 2 (or the Factor you Need)

– i.e. Since 1 Beat is 60, we need to Divide 60 : Given Samples, then Multiply the Result by SR

3) 60 : 67633 = 8.8714089E-4, and 8.8714089E-4 x 44100 = 39.1229134 BPM 

– then Multiply 39.1229134 by 2 (or the Factor you Need) = 78.2458267 BPM

Reverse Vocal Example

– Examine the Amount of Extra Seconds you Need to Extend the Range on Creating a Reversed Vocal

– e.g. we Want the Reversed Vocal Part to Last for 4 Bars at 123 BPM

– so Divide the Current Used BPM through 60000 ms to Evaluate How Many ms there are in 1 Beat (60000 ms = 1 Minute)

– e.g. 60000 ms : 123 BPM = 487.804 ms are in 1 Beat

• a 4 Bar Pattern has 16 Beats, so Multiply 16 x 487.804 = 7804.8780 ms