FIELD NOTES
Straight, dotted and triplet delays
Turn note lengths into milliseconds, with the beat convention in view.
Begin with a quarter note
For this calculator, BPM is the quarter-note tempo. One minute contains 60,000 ms, so a quarter note lasts 60,000 ÷ BPM milliseconds. At 120 BPM that is 500 ms. A half note is 1,000 ms, an eighth note is 250 ms, and a sixteenth note is 125 ms.
The dotted column multiplies each straight value by 1.5. A dotted eighth at 120 BPM is therefore 375 ms. The triplet column multiplies by two thirds: an eighth-note triplet lasts about 166.67 ms, and three of them fill one quarter note. Do not confuse three notes in a beat with a dotted note, which extends a single note’s duration.
Milliseconds and hertz describe the same period
The frequency associated with a repeating interval is 1,000 ÷ its duration in ms. A 500 ms quarter-note cycle repeats at 2 Hz. A dotted eighth of 375 ms repeats at about 2.67 Hz. These numbers can be useful when a modulation effect asks for a rate in Hz instead of a period in milliseconds.
They describe an ideal rhythmic cycle, not an audio pitch or a recommended filter frequency. The table rounds only for display. Use the exported three-decimal values when you want a more detailed reference, while remembering that a plugin’s controls may use their own rounding.
A reverb budget is a starting calculation
You can choose a target note length and subtract a pre-delay. At 120 BPM, a half note lasts 1,000 ms. Subtracting a 30 ms pre-delay leaves a 970 ms decay budget. That arithmetic can help you audition a rhythmic relationship; it does not guarantee silence at 1,000 ms.
Reverb decay controls often describe a level-dependent decay measure, and different algorithms produce different tails. The calculator does not model room dimensions, absorption, RT60, feedback or the sound of a plugin. A pre-delay at least as long as the selected target leaves no positive budget and is rejected.
Audition the relationship
Enter a known tempo in the delay calculator, or get a starting estimate from tap tempo. If the pulse is ambiguous, read half and double tempo first. Compare the result in your actual session and choose what sounds useful, rather than treating any calculated value as an ideal mix setting.
Reviewed 31 October 2026 · Methods & sources