Determine the time signature of the song. Many types of music have a 4/4 timing, meaning four beats are in each measure. However, 3/4 timing is also common. This means three beats are in each measure.
Choose a segment of the song to measure the beats per minute. Make sure no tempo changes exist in that segment.
Count the downbeats of a song for at least 15 seconds. The downbeat is the "1" count, "3" count and so on. These are also referred to as the base beats of a song. Use a watch or clock to measure 15 seconds.
Multiply the number of downbeats by four. Count the downbeats twice before multiplying to ensure the appropriate number. Write the total beats per minute on a piece of paper.