BPM Delay Calculator
Enter the tempo in BPM to get the length of each note value in milliseconds, which you can use as a delay time. You can also work back from a delay time to the BPM.
How the note lengths are calculated
The quarter note counts as one beat (the usual 4/4 way of counting).
- Quarter-note length (ms) = 60,000 ÷ BPM
- Note length = quarter-note length × beats × factor
| Note | Beats | Note | Beats |
|---|---|---|---|
| Whole note (1/1) | 4 | Sixteenth note (1/16) | 1/4 |
| Half note (1/2) | 2 | Thirty-second note (1/32) | 1/8 |
| Quarter note (1/4) | 1 | Eighth note (1/8) | 1/2 |
- Dotted notes are 1.5 times as long as the plain note (a dotted eighth is 1.5 eighth notes).
- Triplets fit three notes into the time of two. Each one is 2/3 as long as the plain note (an eighth-note triplet is 2/3 of an eighth note).
The calculation uses exact fractions and rounds only for display, to the number of decimal places you choose.
Example
At 120 BPM:
- A quarter note is 500 ms (2 Hz), an eighth note 250 ms (4 Hz), a sixteenth note 125 ms (8 Hz) and a whole note 2,000 ms.
- A dotted eighth note is 375 ms (1.5 times 250 ms).
- An eighth-note triplet is about 166.67 ms (2/3 of 250 ms).
Working backwards: a delay of 500 ms taken as a quarter note is 120 BPM, and 375 ms taken as a dotted eighth note is also 120 BPM.
Reverb settings are not decided by BPM alone
A delay set to a note value tends to sit well with the tempo. The best reverb pre-delay or decay time, however, is not decided by BPM alone. It depends on the song, the sound, the space and taste, so use the values here as one starting point that matches the tempo.
This is not the distance-based delay
This tool works out note lengths from the tempo (BPM). To find the time sound takes to travel a distance to a speaker, use a distance-based delay calculation. For the wavelength of a sound, you need the speed of sound, which depends on temperature.
Notes
- BPM can be from 1 to 999, with up to 3 decimal places. Use a period as the decimal separator.
- When you work back from a delay time and the BPM found is outside 1 to 999, the tool says so (the result is still shown).
- Time signatures such as 3/4 or 6/8, and counting the beat in eighth notes, are not taken into account. The quarter note is always one beat.
Frequently asked questions
How many milliseconds is a dotted quarter note?
It is 1.5 times a quarter note. At 120 BPM that is 500 × 1.5 = 750 ms.
Is the Hz value a pitch?
No. Here Hz is how many times per second a note of that length repeats (the repeat rate of the beat). It is not the pitch of a sound. It is useful, for example, for matching an LFO rate to the tempo.
Will a delay set to the BPM always sound good?
It is a good starting point because it sits with the tempo, but not always the best setting. Adjust it by ear for the sound and the song.