Delay and Reverb Time Calculator
Enter your tempo in BPM and pick a note value to get the exact delay time in milliseconds and its Hz equivalent for use as an LFO rate. Choose a reverb size preset to see tempo-synced pre-delay and decay values. Every note division from whole notes to 1/128ths is shown below, including dotted and triplet variants, so you can dial in your plugin or hardware unit without guessing.
Why sync delay and reverb to tempo
When a delay or reverb tail lands on a beat subdivision, the effect blends into the groove rather than fighting it. A random delay time creates rhythmic clutter that muddies a mix; a tempo-synced time reinforces the pulse and makes space feel intentional. The quarter note is one beat at your project tempo. Every other note division - half, eighth, sixteenth - is simply a multiple or fraction of that. Dotted notes add half again (so a dotted eighth is 1.5 eighth notes), and triplets divide the space of two notes into three equal parts. Using these musically meaningful values lets your delay and reverb behave like rhythm instruments rather than random room treatment.
How to read the delay time table
The full table below lists every standard note division from whole notes (1/1) down to 1/128th notes. Each row shows the straight, dotted, and triplet variants, plus the Hz equivalent of each time. The Hz value is what you enter into an LFO rate field if you want a modulation effect (tremolo, chorus, or phaser) that pulses in sync with the same subdivision as the delay. For most mixing tasks, 1/8 and 1/16 straight and dotted values are the most useful: 1/8 dotted is a classic slap-back echo at medium tempo, and 1/16 triplet creates a shimmering wash. Copy the millisecond value directly into your plugin. If your plugin or hardware unit shows only a plain milliseconds field (no BPM sync), these are the numbers to use.
Pre-delay and decay: shaping reverb with tempo
Reverb has two adjustable timings: pre-delay and decay (also called RT60 or reverb time). Pre-delay is the gap between the dry sound and the first reverb reflection - short pre-delays place the sound inside the room, longer ones push it forward in front of the room. Decay is how long it takes the tail to die away by 60 dB. Tempo-syncing decay keeps the reverb from overlapping too far into the next beat, which is the most common cause of a washed-out mix. The presets here use engineering-standard fixed pre-delays (which are largely tempo-independent) combined with tempo-locked decay lengths expressed in beats: a Hall preset uses 8 beats of decay, a Tight Ambience uses just 1 beat. Adjust these starting points by ear, as room acoustics, track density, and the dry-to-wet ratio all affect what sounds best.
Practical tips for delay and reverb in a mix
Start with a high-pass filter on the reverb return to roll off frequencies below 200-400 Hz - low frequencies in reverb tails create mud without contributing to perceived space. For delay, a gentle high-pass on the wet signal and a matching low-pass around 8-12 kHz keep the repeats from competing with the original transient. The dotted 1/8 note delay is a production workhorse across many genres because it creates a syncopated feel that fills space between beats without sounding mechanical. Ping-pong delays use the same time values but alternate between left and right channels; enter the millisecond value into each side independently. For reverb on vocals, try keeping pre-delay around 15-30 ms regardless of tempo - this separates the vocal from its own wash and preserves intelligibility.
Reverb size presets and typical settings
| Preset | Pre-delay (ms) | Decay at 120 BPM (ms) | Best use |
|---|---|---|---|
| Hall | 25 | 4000 | Classical, cinematic, large orchestral spaces |
| Large Room | 12 | 2000 | Live band, rock, pop - open but not washed out |
| Small Room | 6 | 1000 | Drums, tight instruments, natural ambience |
| Tight Ambience | 2 | 500 | Close-mic sounds, vocals, subtle glue |
Pre-delay values are fixed engineering defaults. Decay times shown are calculated at 120 BPM - they scale with your BPM.
Frequently asked questions
What is the formula for delay time from BPM?
The quarter note duration is 60,000 divided by the BPM in milliseconds. For a half note, multiply by 2; for an eighth note, divide by 2; and so on for any other subdivision. A dotted note is 1.5 times the straight value, and a triplet is 2/3 of the straight value. At 120 BPM: quarter = 500 ms, eighth = 250 ms, dotted eighth = 375 ms, eighth triplet = 166.67 ms.
What is the difference between straight, dotted, and triplet delays?
A straight delay lands exactly on the note subdivision: a 1/8 delay repeats every eighth note. A dotted delay adds half the note length again, so a dotted 1/8 is 1.5 times an eighth note long - this creates a syncopated feel because repeats land slightly off the beat grid. A triplet delay divides two note spaces into three equal parts, giving a more fluid, rolling feel. Dotted eighths are a classic for rhythmic lead guitar and synth arpeggios; triplets appear often in melodic house and ambient music.
What does Hz mean in a delay calculator?
Hz (Hertz) is the frequency equivalent of a delay time: the number of repetitions per second. A 500 ms delay repeats twice per second, so its Hz equivalent is 2 Hz. This matters when you set an LFO (low-frequency oscillator) to pulse at the same rate as your delay - entering the Hz value into your LFO rate field locks it to the same subdivision. For very short delay times (under about 25 ms), Hz values enter audio-frequency territory where the repetitions fuse into a pitch rather than a distinct echo.
What is reverb pre-delay and why does it matter?
Pre-delay is the time between the dry (original) signal and the first reverb reflection. A short pre-delay (2-6 ms) makes an instrument sound like it is sitting inside the room. A longer pre-delay (20-30 ms) separates the dry transient from the reverb tail, which preserves attack and clarity while still adding space - this is especially useful on vocals and snare drums. Pre-delay works somewhat independently of BPM because it is mostly an acoustic simulation of physical room size; however, keeping it shorter than the smallest note subdivision in your track prevents rhythmic smearing.
How do I set reverb decay to match my song tempo?
A common approach is to set the RT60 (decay) to a musically meaningful number of beats. For a relaxed, spacious sound, use 4-8 beats; for a tighter, punchy feel, use 1-2 beats. Multiply the number of beats you want by the quarter-note duration (60,000 / BPM) to get milliseconds. At 120 BPM, 4 beats = 2000 ms. This calculator does that multiplication automatically once you choose a preset and enter your tempo.
What reverb preset should I use for vocals?
Large Room is a solid starting point for most vocal reverb: it adds space without sounding like a cathedral, and its pre-delay of 12 ms keeps the voice forward in the mix. For intimate or close-mic vocal recordings, try Small Room or Tight Ambience and blend in just a touch of the wet signal. Save Hall for special moments - a bridge, a key outro line - rather than using it throughout a song, because long decays can make lyrics hard to understand.
Can I use these delay times for chorus, flanger, or phaser effects?
Yes, particularly the Hz values. Chorus and flanger effects modulate delay time with an LFO, and setting that LFO to a tempo-synced Hz value creates a modulation that moves in time with the track. Phasers and tremolos work the same way: enter the Hz equivalent of the note value you want into the LFO rate or speed knob. Very slow rates - 1/4 or 1/2 note Hz values - produce a slow, sweeping motion; 1/8 and 1/16 rates create faster, more rhythmic pulsing.