Use a BPM detection app or website
Tap along with the beat using a tap tempo tool
Check the song’s metadata in a DJ or music library app
Search the song title plus “BPM” online
Count the beats for 15 seconds and multiply by 4
Count the beats for 30 seconds and multiply by 2
Use audio editing software with tempo detection
Use a DAW or DJ software that analyzes track tempo
Match the song to a metronome until the tempos align
Look up the BPM in sheet music or official track data