Reverb & Delay Time Calculator

Every calculator on the site, and when to open each one

The console above is the combined page: one tempo in, a reverb table and a delay grid out. The specialist tools below it go deeper on one job each, and every paragraph here points to the right one — start with the job you are actually doing, not the longest menu.

If you need repeats rather than wash, the full delay grid with dotted and triplet values gives every note value in milliseconds and Hz, including the settings guitar players type into pedals. If the wash itself is burying your source, the pre-delay timing tool finds the short gap that lets a transient through before the tail starts, while the decay and tail-length calculator works the other end of the same reverb, trimming the total so the tail finishes on the grid instead of under the next chord.

Reverb type changes the character even when the timing math stays the same. Open the plate presets for bright, dense tails when a vocal or snare needs shine, the hall timings from club to cathedral for the longest spaces on the site, or the small-room timings for believable close spaces when realism matters more than size. For a short, splashy, unmistakably retro sound, the spring timings built for guitar and dub keep the boing short and bright, and the smooth chamber presets in the Abbey Road tradition sit between room and hall — musical, even, and rarely muddy.

Two tools are organized around a source rather than a space. The vocal settings by genre, built around pre-delay for clarity pairs longer gaps with ballad, pop, rock and shoegaze tail lengths, and the snare rule that ends the tail before the next hit extends the same logic across a full drum kit, with separate targets for kick, toms and overheads. Not sure of the tempo in the first place? Tap it out or convert in either direction with the tap-tempo and BPM conversion tool. The one calculator here doing a genuinely different job is the acoustic RT60 estimator based on room size and surfaces, which predicts how long a real room rings rather than syncing a plugin to a song. Finally, if you want every tempo side by side on paper, the printable BPM to milliseconds chart lays out the complete grid for the studio wall.

How it works: two formulas run the whole site

Musical reverb and delay are arithmetic before they are taste. A tempo in beats per minute tells you exactly how long one beat lasts, and every useful timing on this page is a note value derived from that beat — so the space you add pulses with the track instead of smearing across it.

Pick a total reverb time that lands on a bar or note boundary, choose a very short note value as the pre-delay, and set the decay to whatever remains. That one invariant — decay equals total minus pre-delay — is enforced on every tool here, so the three numbers you type into a plugin always add up to a tail that ends where the music says it should.

Change the tempo and every value rescales proportionally — double the BPM and every time halves. That is why a setting copied from another song so often disappoints: the numbers were right for that tempo, not for yours.

Reverb sizes explained: four totals, tied to the bar

The four sizes in the console are not arbitrary plugin presets. Each total is a note value, which means each one locks to any tempo and always resolves on a musical boundary.

Hall — total of 2 bars

The longest standard size here: 4000 ms at 120 BPM, with a 62.5 ms pre-delay taken from a 1/32 note. Use it for strings, pads and ballad vocals that are supposed to sound far away and grand. Because the total is a whole number of bars, even this much wash clears out before the next section lands.

Large Room — total of 1 bar

At 120 BPM that is 2000 ms total, a 31.25 ms pre-delay (a 1/64 note) and 1968.75 ms of decay. This is the all-rounder for full-band mixes: clearly a space, clearly audible, but short enough that a busy arrangement stays readable.

Small Room — total of a 1/2 note

1000 ms at 120 BPM, with the 15.63 ms pre-delay and 984.38 ms decay from the worked example above. Intimate and present — the size for acoustic guitar, close vocals and spoken voice that needs a believable place to sit without sounding like a concert.

Tight Ambience — total of a 1/4 note

Just 500 ms at 120 BPM, a 3.91 ms pre-delay and 496.09 ms of decay. Ambience at this length is felt more than heard: it glues dry, close-miked recordings together and then gets out of the way within a single beat.

Delay or reverb? And what the Hz column is for

Delay and reverb solve different problems, even though both are timed from the same grid. A delay repeats the source at distinct intervals — you hear separate echoes — so it adds rhythm and width while leaving gaps for the dry signal to stay intelligible. Reverb is thousands of reflections merged into a continuous wash, so it adds distance, size and sustain, but it fills those gaps in. A practical rule: if a part needs energy and movement without losing definition, reach for a dotted or triplet delay first; if it needs to sit further back in an imaginary room, reach for reverb; most finished mixes use a short delay for presence and a tempo-fitted reverb for depth, on different sends.

Using the Hz values for modulation

Every millisecond value on this site has a frequency twin, because Hz is simply 1000 divided by ms. A 500 ms quarter note at 120 BPM is 2 Hz; a 250 ms 1/8 note is 4 Hz; a 62.5 ms 1/32 note is 16 Hz. Type those rates into an LFO, tremolo, vibrato or filter sweep and the modulation pulses in time with the track instead of drifting against it. Slow rates around 0.5 to 2 Hz suit whole-note and half-note movement; faster rates suit short note values and should usually be kept subtle, because a fast, deep modulation reads as a special effect rather than groove.

Limitations, stated plainly

Tempo sync is a starting framework, not a mix decision. These totals assume a steady tempo in 4/4 and say nothing about EQ, damping, diffusion or level — a 3937.5 ms hall decay sent too loud will still bury a mix, and a tail that is technically on the grid can still be the wrong length for a sparse arrangement. Songs with tempo changes, rubato performances or swung grids need the values treated as approximations around the local tempo. Real rooms also do not behave like note values at all; that acoustic question belongs to the RT60 tool linked above, not to this console. Set the numbers, then solo the return, listen in context, and shorten or lengthen by ear — the grid gets you close in seconds, and your ears finish the job.

Frequently asked questions