Delay & Reverb Calculator
Enter your song tempo to get millisecond delay times for every note subdivision.
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Enter your song tempo in BPM and the calculator instantly displays the delay time in milliseconds for every common note subdivision. Here is how to use the values:
- Set your BPM. Type the tempo directly, or use the BPM Calculator to tap it from a reference track.
- Choose your subdivision. Quarter note delay creates a standard echo that falls on every beat. Dotted eighth is the classic U2-style slap delay that lands between beats for a syncopated feel. Eighth note is tight and subtle. Whole note creates long, ambient echoes.
- Enter the value into your gear. Set the delay time on your pedal, plugin, or DAW in milliseconds. For reverb pre-delay, smaller values like 15-30ms work best to push the room sound slightly behind the dry signal.
- Copy all values to paste the full table into your session notes.
About Tempo-Synced Delay
Delay effects repeat a signal after a set time. When that time is mathematically related to the song tempo, the echoes lock to the groove and feel musical instead of random. A quarter note delay at 120 BPM is 500ms. An eighth note is 250ms. The dotted eighth note, at 375ms at 120 BPM, is particularly popular in rock because it creates a three-against-four polyrhythm that feels wider and more alive than a straight delay.
Reverb pre-delay is a similar concept: a short gap between the dry signal and the reverb onset. Values between 10ms and 30ms help the dry signal cut through a dense mix while keeping the sense of space. For pre-delay, use a fraction of the quarter note value or just set it by ear starting around 20ms.
Frequently Asked Questions
What is the dotted eighth delay and why is it so popular?
A dotted eighth note is 1.5 times an eighth note, which equals 75% of a quarter note. At 120 BPM, that is 375ms. This delay time creates echoes that land on the offbeats in a way that feels syncopated and rhythmically interesting without cluttering the mix. The Edge from U2 popularized this sound, and it remains one of the most-used delay settings in rock, pop, and country music.
How do I set delay time without a calculator?
The formula is: delay (ms) = 60,000 / BPM for a quarter note. Divide by 2 for eighth note, by 4 for sixteenth. Multiply by 1.5 for dotted values, by 0.667 for triplets. For example, at 100 BPM: quarter = 600ms, eighth = 300ms, dotted quarter = 900ms. A calculator is faster, but knowing the formula helps when you are troubleshooting in a live situation.
What is pre-delay in reverb and how should I set it?
Pre-delay is the time gap between the dry signal and the onset of reverb. A short pre-delay of 10-30ms lets the attack of a note speak clearly before the room effect arrives, which preserves clarity in dense mixes. For vocals, 20-40ms is a common starting point. You can set it to a musical subdivision for rhythmic cohesion, or just dial it in by ear. Long pre-delay settings of 80-150ms can create a dramatic effect where the reverb feels like a separate event.
Do I always need to sync delay to the BPM?
No. Tempo-synced delay sounds musical and controlled, which is great for most produced music. But free-running delays at odd times like 317ms can create a washy, ambient texture that feels less rhythmically locked, which suits certain atmospheric or experimental styles. Some engineers intentionally set delay slightly off-tempo to avoid echo buildup cluttering the mix. Use your ears, not just the math.