Detect BPM

What is BPM?

BPM stands for beats per minute: how many beats of the underlying pulse happen in sixty seconds. A song at 120 BPM has two beats every second. At 60 BPM there is one beat per second, the same as a ticking clock. Musicians use BPM to set a metronome, DJs use it to match two tracks, producers use it to time delays and loops, and runners use it to pick music that matches their stride.

How to use Detect BPM?

Start the song, or find the pulse you want to measure.Tap in time with the beat: click anywhere on the yellow area, press space, or tap the screen on a phone. Aim for at least eight taps in a row.Read the number. It is the average of your last eight taps, so it settles after a few beats. Stop tapping for two seconds and the next tap starts a fresh measurement.

How accurate is tapping the tempo?

After eight or more even taps the reading is usually within one or two BPM of the real tempo. Human timing wobbles by about 20 milliseconds per tap, and averaging cancels most of that out. The mistake that matters is tapping at half or double speed: if you tap every other beat of a 140 BPM song you will read 70. When a number feels wrong, double it or halve it and see which one matches the music.

Tapping or automatic BPM detection?

Tapping works with anything you can hear: a record, a live band, the radio, a song stuck in your head, or your own pulse. It takes ten seconds and needs no file. Automatic detectors analyse an audio file and are better when you need a precise decimal tempo for sampling or DJ mixing, but they need the file, and they are fooled by the same half-time and double-time ambiguity you are.