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Delay & Reverb Time Calculator
Enter your tempo and get every delay time in milliseconds, plus reverb pre-delay and decay starting points for five room sizes — so your effects breathe with the track instead of against it.
Delay + reverb Any tempo No signup
Values update instantly. Switch your plugin off tempo-sync and type the milliseconds in directly.
1/8 250.0 ms · dotted 1/8 375.0 ms
Made with Drumloop AI — describe a beat and hear it in seconds.
Generate drum loops with Drumloop AIHow to sync delay to tempo
- Enter your project tempo. If you don't know it, tap it in or detect it from the audio.
- Pick a note division: quarter for obvious throws, eighth for drive, dotted eighth for the rolling cross-rhythm.
- Copy the millisecond value into your delay plugin with tempo-sync switched off.
- Set reverb pre-delay from the table below so the transient stays clear, then set decay so the tail dies before the next downbeat.
Delay times at 120 BPM
| Division | Milliseconds | Hz | What it is for |
|---|---|---|---|
| 1/1 — whole | 2000.0 | 0.50 | Ambient washes and one-per-bar throws. |
| 1/2 — half | 1000.0 | 1.00 | Slow dub echoes on sparse arrangements. |
| 1/4 — quarter | 500.0 | 2.00 | The default vocal throw. Lands on every beat. |
| 1/8 — eighth | 250.0 | 4.00 | Adds drive without blurring the words. |
| 1/8 dotted | 375.0 | 2.67 | The Edge / synthwave delay. Creates a rolling cross-rhythm. |
| 1/8 triplet | 166.7 | 6.00 | Shuffles against straight material. Great on guitars. |
| 1/16 — sixteenth | 125.0 | 8.00 | Thickens percussion; short enough to read as texture. |
| 1/16 dotted | 187.5 | 5.33 | Subtle syncopation on hats and plucks. |
| 1/32 — slapback | 62.50 | 16.00 | Rockabilly slap. Reads as space, not repeats. |
Reverb pre-delay and decay
Five starting points, scaled to your tempo. Pre-delay is set from a short note value so the transient survives; decay is set in beats so the tail clears before the next landmark. Treat these as the first setting you try, not the last.
| Space | Pre-delay | Decay | Total | Use it on |
|---|---|---|---|---|
| Tight ambience | 31 | 250 | 281 | Glue without a visible tail — drum bus, room mics. |
| Small room | 63 | 500 | 563 | Close, dry space. Snares and spoken vocals. |
| Big room | 125 | 1000 | 1125 | Obvious space that still clears each bar. |
| Hall | 125 | 2000 | 2125 | One-bar tail. Pads, ballad vocals, cinematic drums. |
| Cathedral | 250 | 4000 | 4250 | Two-bar wash. Ambient and sound design only. |
All values in milliseconds.
Getting effects to sit in the groove
An untimed delay fights the track. Because the repeats fall between the beats at no fixed relationship, the ear reads them as clutter and the usual response is to turn the effect down until it disappears. A delay locked to a note division does the opposite: the repeats reinforce the pulse, and you can push the level far higher before the mix feels crowded.
Start with the quarter note. It is the most obvious choice and the easiest to hear working. Move to the eighth when the arrangement is sparse and needs energy, and to the sixteenth when you want thickness rather than audible echoes.
The dotted eighth deserves its reputation. At three sixteenths long it never aligns with the beat the same way twice in a bar, so a single played note generates a pattern that moves. Pair it with modest feedback and roll the top off the repeats and you have the sound of a great deal of guitar and synth music from the last forty years.
Reverb works the other way round: rather than adding rhythm, it must avoid destroying it. Long tails at fast tempos wash the transients away. That is why the decay column here is measured in beats — a two-second hall is generous at 70 BPM and unusable at 170.
A quick working order
Set the delay division first, because it changes how much space is left. Then set reverb pre-delay so the source keeps its attack. Then set decay by ear against the busiest bar in the arrangement, not the sparsest — if it survives the chorus it will survive the verse. Finally, high-pass the returns so the low end stays tight; almost every muddy mix is a reverb or delay return carrying bass it does not need. If you want a neutral reference to tune against, generate a drum loop at your tempo and solo it with the effect.
Frequently asked questions
How do I calculate delay time from BPM?
Divide 60,000 by the tempo to get one beat in milliseconds — that is your quarter-note delay. At 120 BPM that is 500 ms. Halve it for an eighth (250 ms), halve again for a sixteenth (125 ms). Multiply any of those by 1.5 for the dotted version or by two-thirds for the triplet.
What is a dotted eighth delay and why is it so popular?
A dotted eighth is three sixteenths long — 375 ms at 120 BPM. Because it does not divide evenly into the bar, the repeats drift across the beat and land in the gaps of the source part, generating a rolling pattern from a single note. It is the sound behind a great deal of stadium rock guitar and most synthwave arpeggios. Set the feedback low and it thickens; set it high and it becomes a rhythmic part in its own right.
Why not just use the tempo-sync button in my delay plugin?
Often you should. Manual values matter when the plugin syncs to the host but you want the delay slightly loose, when you are working with material that has no tempo map, when the delay is on a bus that receives audio at a different tempo, or when you want to detune a repeat deliberately by nudging a few milliseconds off the grid. Hardware units and many older plugins also take milliseconds only.
What pre-delay should I use on reverb?
Enough to let the transient through before the reverb starts, which is typically 10–40 ms. Setting it in time with the track keeps it musical: a 1/64 note at 120 BPM is 31 ms, which is a sensible vocal starting point. Shorter pre-delay glues a source into the space; longer pre-delay keeps it forward and dry-sounding while still giving it a tail.
How long should the reverb decay be?
As a starting point, short enough that the tail has faded before the next musical landmark. One beat of decay works on fast material; one bar suits ballads and cinematic drums. At 120 BPM a one-bar tail is two seconds. If the mix sounds cluttered, shorten the decay before you reach for the level — a shorter, louder reverb usually reads as more space than a long quiet one.
Should reverb and delay be on the same tempo grid?
Usually yes, and it is the fastest way to make a busy mix sound intentional. Put the delay on a note division and the reverb pre-delay on a shorter one, so the repeats and the tail interlock rather than smearing. When you deliberately want a sound to float outside the groove — a pad, a transition effect — take it off the grid on purpose.
What is the difference between pre-delay and decay?
Pre-delay is the silence between the dry sound and the first reflection: it controls how far away the source feels and how much of the attack survives. Decay is how long the tail takes to fade to silence: it controls how big the space feels. Pre-delay protects clarity; decay creates size.
Can I hear these settings on real drums?
Generate a loop at your tempo with Drumloop AI, drop it into your session, and you have a musical reference to tune against in seconds. The free drum loop library is also organised by tempo.
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Tune your effects against a real groove.
Drumloop AI generates original, royalty-free drum loops at your exact tempo — a reference to dial delays and reverbs against in seconds.