Reverb Calculator

How do you set a reverb from BPM?

1. Enter the song's BPM. This calculator counts quarter-note beats, so check the beat unit if your DAW displays a dotted-quarter tempo in 6/8.
2. Choose a pre-delay note. Start at 1/64 for some separation between the dry attack and the reverb, or 1/128 for a closer response.
3. Choose the total duration. One or two beats gives a shorter starting point; four or eight leaves more space for a sustained tail.
4. Copy pre-delay in milliseconds and decay in seconds. Listen in the full mix, then adjust the values and return level to suit the arrangement.

Need repeat timings or a modulation rate instead? The delay calculator converts BPM to milliseconds and hertz for every note from 1/1 to 1/64.

What is the reverb timing formula?

Decay target = total musical duration − pre-delay. The total is a number of quarter-note beats. It gives you a consistent way to try shorter or longer tails without guessing both controls independently.

Dotted pre-delay multiplies the straight value by 1.5. Triplet pre-delay multiplies it by 2/3. The total stays fixed, so increasing pre-delay makes the suggested decay a little shorter.

This is a tempo calculation, not an acoustic measurement. Many reverbs specify decay as RT60, a 60 dB reduction in level, rather than the instant a tail stops. See FabFilter's explanation of reverb controls. Frequency-dependent damping can also make the highs fade earlier than the lows.

Which starting point should you use?

The preset buttons change timing, not the sound of the reverb algorithm. Select a room, plate or hall in your plugin, then use these values as a first pass.

• Tight room: a 1/128-note pre-delay and a one-beat total. Try it on percussion when the attack should stay close.
• Room: a 1/64-note pre-delay and a two-beat total. Try it on snare, guitar or backing vocals.
• Plate: a 1/64-note pre-delay and a four-beat total. Try it on a sustained lead vocal, then shorten the tail if words overlap.
• Hall: a 1/32-note pre-delay and an eight-beat total. Try it on pads or sparse phrases with space between notes.

For example, at 120 BPM the Plate setting gives 31.25 ms of pre-delay and a 1.969-second decay. At 90 BPM, the same musical settings become 41.67 ms and 2.625 seconds. The slower song leaves a longer timing budget, but a dense arrangement may still need a shorter tail.

What should you listen for after setting the numbers?

For a step-by-step vocal exercise, read reverb pre-delay versus decay. It separates onset, tail length and ducking, with worked examples for common tempos.

Loop the busiest section and listen to the dry attack, the end of each phrase and the next downbeat. If the reverb hides consonants or transients, lower the return first, then shorten the decay. If the reverb sounds detached, reduce pre-delay.

If the timing works but the mix still feels cloudy, check the reverb return's low end. The EQ frequency chart helps identify the region you are hearing. Compare bypassed and active at a similar perceived level: a louder return can seem impressive while making the part harder to place.

Tempo sync is an option, not a requirement. Adjust either setting away from the grid when it makes the part sit better. On a tempo change, recalculate for that section or use your plugin's host-sync controls.