Delay and reverb calculator
Type or tap a tempo. Get the delay and reverb times, and hear them.
Tempo
1/4 note delay
Delay times at 120 BPM, in ms
Press a number to choose and copy it
| Note | Straight | Dotted | Triplet |
|---|---|---|---|
| 1/1 | 2000 | 3000 | 1333.3 |
| 1/2 | 1000 | 1500 | 666.7 |
| 1/4 | 500 | 750 | 333.3 |
| 1/8 | 250 | 375 | 166.7 |
| 1/16 | 125 | 187.5 | 83.33 |
| 1/32 | 62.5 | 93.75 | 41.67 |
| 1/64 | 31.25 | 46.88 | 20.83 |
Reverb times at 120 BPM
Press a number to choose and copy it
| Pre-delay, in ms | ||||
|---|---|---|---|---|
| Length: decay, in s | 1/12815.63 | 1/6431.25 | 1/3262.5 | 1/16125 |
| 2 bars, Hall | 3.98 | 3.97 | 3.94 | 3.88 |
| 1 bar, Large room | 1.98 | 1.97 | 1.94 | 1.88 |
| 1/2 note, Small room | 0.984 | 0.969 | 0.938 | 0.875 |
| 1/4 note, Tight ambience | 0.484 | 0.469 | 0.438 | 0.375 |
Pre-delay plus decay adds up to the length. Bars are 4/4. The room names are loose labels, longest to shortest.
You’ve got the numbers. Can you hear them?
Match the Space plays a part in a room. You rebuild it by ear: how much reverb, and how long it hangs on.
Start Match the SpaceFree to start, no account needed · Then: Echo (Pro), match a delay by ear
What Hear it plays
A snare on beat one and a soft tick on every beat, at your tempo. Choose Delay or Reverb, press a number, then Hear it. Press another number while it plays to compare the two. The picture above the table shows the same loop, left to right.
Switch from Snare to Music to hear the same delay or reverb on a lead vocal. The tempo then follows the song, so the times sit in time with it.
- Delay: the snare, then its repeats at that time, each quieter than the one before.
- Reverb: the snare in a reverb of the length and pre-delay you chose. It’s the room Match the Space uses.
How delay times are worked out
Short answer: a quarter-note delay is 60,000 divided by the tempo, in milliseconds. At 120 BPM that’s 500 ms. Halve it for an eighth note, and halve it again for a sixteenth.
- Dotted: one and a half times the straight value.
- Triplet: two thirds of the straight value.
- Rate in Hz: 1,000 divided by the milliseconds. It’s shown beside the delay time, for an LFO or a tremolo that won’t sync to the tempo.
Most delay plugins sync to the session’s tempo by themselves. The numbers are for the ones that don’t, for hardware, and for nudging a delay just off the grid.
Delay times at common tempos
In milliseconds. For any other tempo, or to hear one, use the calculator above.
| BPM | 1/4 note | 1/8 note | Dotted 1/8 | 1/16 note |
|---|---|---|---|---|
| 60 | 1000 | 500 | 750 | 250 |
| 70 | 857.1 | 428.6 | 642.9 | 214.3 |
| 80 | 750 | 375 | 562.5 | 187.5 |
| 90 | 666.7 | 333.3 | 500 | 166.7 |
| 100 | 600 | 300 | 450 | 150 |
| 110 | 545.5 | 272.7 | 409.1 | 136.4 |
| 120 | 500 | 250 | 375 | 125 |
| 130 | 461.5 | 230.8 | 346.2 | 115.4 |
| 140 | 428.6 | 214.3 | 321.4 | 107.1 |
| 150 | 400 | 200 | 300 | 100 |
| 160 | 375 | 187.5 | 281.3 | 93.75 |
| 170 | 352.9 | 176.5 | 264.7 | 88.24 |
| 180 | 333.3 | 166.7 | 250 | 83.33 |
Reverb and pre-delay times are a starting point
Pre-delay is the gap before the reverb starts. It keeps the dry sound clear of its own room. Decay is how long the tail takes to die away.
The table sets the two so that together they last a musical length: a beat, half a bar, a bar or two bars. The tail has then mostly faded by the time the next one starts. It’s a rule of thumb, not a law. Start from the number, then set it by ear, because the song, the part and the reverb itself all change what works. What is reverb? has the parts of a reverb, with sound.
Questions
How do I convert BPM to milliseconds?
Divide 60,000 by the tempo. That’s one quarter note in milliseconds: 500 ms at 120 BPM, 600 ms at 100 BPM.
What is a dotted eighth delay at 120 BPM?
375 ms. A dotted eighth lasts three quarters of a beat, and a beat at 120 BPM is 500 ms.
How do I work out a reverb time from the tempo?
Pick a musical length, such as one bar, and split it between pre-delay and decay. At 120 BPM a bar is 2,000 ms: a 31.25 ms pre-delay leaves a decay of about 1.97 seconds.
How long should reverb pre-delay be?
A 1/64 note at the song’s tempo is a common place to start: 31.25 ms at 120 BPM. Shorter keeps the reverb tight against the sound, and longer pulls the two apart. At slow tempos a 1/64 note is long enough to hear as a separate echo, so pick 1/128. Set it by ear.
Should reverb decay match the tempo?
It’s a useful starting point, not a rule. A tail that has mostly faded by the next beat or bar stays out of the way of what comes next. Then listen and adjust.