Music Calculator: BPM, Delay & Notes

Tap a tempo, turn BPM into delay and reverb times, note names into frequencies, and look up scales and chords.

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 BPM, average
0Taps
 One beat

Delay times are rounded to two decimal places of a millisecond. Notes use equal temperament from the reference A4 you set, with MIDI numbering where middle C is C4. Notes are spelt from the scale or chord degree, so you will see both sharps and flats.

How to use it

  1. Tap tempo: tap the big button in time with a song to measure its BPM, then send it to the delay tab.
  2. Delay and reverb: type a tempo to see every note length in milliseconds and hertz, with dotted and triplet values, and reverb settings that fit the tempo.
  3. Notes and scales: convert between note names and frequencies, or pick a root and a scale or chord to list and hear its notes.

Questions

How is a delay time worked out from BPM?

One beat, a quarter note, lasts 60,000 divided by the BPM in milliseconds: 500 ms at 120 BPM. Halve it for an eighth note, double it for a half note. A dotted note is one and a half times as long, a triplet two thirds as long.

Why show the time in hertz?

Modulation effects such as tremolo, auto pan and filter sweeps set their speed as a rate in hertz. The hertz value is one second divided by the note length, so the effect cycles once per note.

What is cents in the frequency result?

A cent is a hundredth of a semitone. The result shows how far your frequency is above or below the nearest note, from minus 50 to plus 50 cents.

Why is the same note sometimes called D# and sometimes Eb?

Notes in a scale or chord are named from their degree: in B major the third is D#, while in C minor it is Eb, even though both are the same key on a piano.