Play a song and tap the pad, or press the space bar, on every beat. After four or five taps the tempo settles to within a beat per minute, and the longer you tap the more accurate it gets. The tool averages every interval, ignores a missed or doubled tap, and shows how steady your tapping was, the tempo of your last four taps, and the half-time and double-time readings in case the song feels twice as fast or slow as the number.
Use it to set a practice tempo for a piece you are learning, to match a backing track, or to find the BPM of a song for a DJ set or a video edit. One button opens the metronome at the tempo you found, and another gives the delay times in milliseconds.