Delay Calculator

How to use it

1. Type the song's tempo into the BPM field, pick a common tempo, or tap along with the track: tap the button (or press T) on each beat. Four or more taps give a steady reading, and a long pause starts a new count.
2. Read the note value you want from the table. The top number in each cell is the delay time in milliseconds; the smaller number under it is the same length as a rate in hertz.
3. Click a value to copy it, then paste it into your delay, reverb or modulation plugin. The table and the reverb cards update as you change the tempo.

How the numbers work

One beat (a quarter note) lasts 60,000 ÷ BPM milliseconds. Every other value follows from that:

The calculator keeps two decimal places. That is far finer than anyone can hear, but it means a value pasted into a plugin that accepts decimals lines up exactly with the host grid.

Straight, dotted or triplet

Straight values repeat on the grid: a quarter-note delay echoes on the next beat, an eighth note in between. They thicken a part without changing its rhythm.

Dotted values are one and a half times as long, so the repeats fall between the beats and weave a new rhythm against the original. A dotted eighth over straight sixteenths is the classic example: one note played becomes a flowing figure.

Triplet values fit three in the space of two. They suit shuffles, swung hi-hats and half-time trap patterns, and they sound more relaxed than straight repeats at the same tempo.

Reverb pre-delay and decay

The reverb cards turn the tempo into two settings. Pre-delay is a small note value (a 1/128, 1/64 or 1/32 note), so the gap before the space arrives is part of the groove. The decay is then chosen so that pre-delay plus decay ends on a musical boundary: the next beat for a tight room, half a bar for a room, the next downbeat for a plate and two bars for a hall.

These are starting points, not measurements of real rooms. Reverb plugins define decay differently: most follow RT60 (the time for the tail to fall 60 dB), some use their own scale. Set the numbers, then listen to the tail against the next hit and shorten it if it clouds the downbeat.

Hertz: LFOs and modulation

The hertz values are the same note lengths expressed as a rate. Use them for anything that cycles: tremolo, auto-pan, a filter LFO, chorus or phaser rate, or a sidechain-style volume shape. A 1/4-note rate at 120 BPM is 2 Hz, one full cycle per beat. Plugins that can sync to the host do this for you; the numbers matter when a plugin only accepts hertz.

Common mistakes

• Reading the wrong tempo. Half-time and double-time feels fool the ear. If the delay sounds twice as busy as expected, halve the BPM (or use the next longer note value).
• Forgetting tempo changes. A synced value is only right at one tempo. If the song ramps or the tempo map changes, recheck the section you are working on or let the plugin sync to the host.
• Syncing everything. When every delay and tail lands exactly on the grid the mix can feel stiff. Try a value a few milliseconds short to push the feel, or long to lay it back.
• Too much feedback on long values. A half-note delay with high feedback stacks repeats under the next several bars. Filter the repeats or lower the feedback before turning the delay down.
• Pre-delay that is longer than the groove allows. At fast tempos a 1/32 pre-delay can be long enough to sound like a slap echo. Drop to the 1/64 or 1/128 value.