Delay time is the interval between the original sound and its repeat. When delay is synchronized to a song, the time is usually calculated from the tempo in beats per minute (BPM) and then matched to a musical subdivision such as a quarter note, eighth note or dotted eighth note.
The basic quarter-note formula is:
Quarter-note delay in milliseconds = 60,000 ÷ BPM
Once the quarter-note value is known, multiply or divide it to get other subdivisions.
BPM to delay time formula
Because one minute contains 60,000 milliseconds, the duration of one beat at a given BPM is:
Beat time (ms) = 60,000 ÷ BPM
For example, at 120 BPM:
60,000 ÷ 120 = 500 ms
So one quarter note is 500 ms at 120 BPM. This is a timing reference; the best audible setting may be slightly different depending on the effect and arrangement.
You can use the delay calculator for a direct conversion or the BPM reverb sync guide for related timing ideas.
Common musical delay subdivisions
| Note value | Calculation from quarter note | Example at 120 BPM |
|---|---|---|
| Whole note | Quarter note × 4 | 2,000 ms |
| Half note | Quarter note × 2 | 1,000 ms |
| Quarter note | Quarter note × 1 | 500 ms |
| Eighth note | Quarter note ÷ 2 | 250 ms |
| Sixteenth note | Quarter note ÷ 4 | 125 ms |
| Dotted eighth | Quarter note × 3 ÷ 4 | 375 ms |
| Dotted quarter | Quarter note × 3 ÷ 2 | 750 ms |
| Quarter-note triplet | Quarter note × 2 ÷ 3 | About 333.3 ms |
Plugin labels can differ, especially for triplets and dotted values. Confirm the selected note division in the plugin or enter the millisecond value manually.
Delay time chart by BPM
The chart below shows common quarter-note and eighth-note values. Round values are suitable starting points; plugins may display more precise decimals.
| BPM | Quarter note | Eighth note | Dotted eighth |
|---|---|---|---|
| 60 | 1,000 ms | 500 ms | 750 ms |
| 80 | 750 ms | 375 ms | 562.5 ms |
| 90 | 666.7 ms | 333.3 ms | 500 ms |
| 100 | 600 ms | 300 ms | 450 ms |
| 110 | 545.5 ms | 272.7 ms | 409.1 ms |
| 120 | 500 ms | 250 ms | 375 ms |
| 128 | 468.8 ms | 234.4 ms | 351.6 ms |
| 140 | 428.6 ms | 214.3 ms | 321.4 ms |
| 160 | 375 ms | 187.5 ms | 281.3 ms |
| 180 | 333.3 ms | 166.7 ms | 250 ms |
How to choose the right delay division
Quarter-note delay
Quarter-note repeats are easy to hear and can create a spacious, deliberate echo. They work well on exposed vocals, guitars and synths, but may overlap the next phrase in a busy arrangement.
Eighth-note delay
Eighth-note delay is shorter and often fits rhythmic vocal, guitar and keyboard parts. It can add movement without creating as much space as a quarter-note repeat.
Dotted-eighth delay
Dotted-eighth delay places the repeat between regular eighth-note positions and can create a syncopated rhythmic feel. It is common in rhythmic guitar, vocal and keyboard effects.
Sixteenth-note delay
Sixteenth-note delay is short and can add texture, width or density. With low feedback it may feel more like thickening than a clearly separate echo.
Triplet delay
Triplet divisions introduce a three-part rhythmic feel. They can contrast with a straight beat and are useful for fills, riffs and transitional effects.
Delay time for common mixing tasks
Vocal delay
Choose a division that leaves space for the next lyric. Filter the repeats and automate the send on phrase endings so the delay supports the vocal without repeating every word at equal volume.
Guitar delay
Match the delay to the picking pattern or use a short slapback for thickness. Dotted and eighth-note divisions can reinforce rhythmic parts, while longer repeats suit exposed lead lines.
Drum and percussion delay
Short delays can widen percussion or create a rhythmic accent. Keep feedback and low-frequency repeats controlled so the groove remains clear.
Synth and keyboard delay
Tempo-synced repeats can reinforce the pattern, but long feedback may fill the gaps between chords. Filter the return and shorten the tail when the arrangement becomes dense.
When not to sync delay to BPM
Tempo sync is useful, but it is not mandatory. A free-time delay can create a natural slap, an offset echo or a sound-design texture that intentionally sits outside the grid.
Use unsynchronized delay when the goal is a specific distance, groove displacement or expressive timing. Listen for clashes with the next phrase and adjust by ear.
Delay time, feedback and mix
Delay time controls the spacing of repeats, but it is only one part of the result.
Feedback
Feedback controls how many repeats remain audible. Low feedback creates one or a few echoes; high feedback creates a longer trail and can build up quickly.
Wet level
Wet level determines how prominent the repeats are beside the dry source. On a send, keep the return fully wet and control the send level; on an insert, set the balance directly.
Filtering
High-pass and low-pass filters make repeats less intrusive. Darker repeats often sit behind the source more naturally, while bright full-range repeats can compete with vocals and cymbals.
Stereo offset
Different left and right delay times can create width, but extreme offsets may weaken mono compatibility. Check the effect in context and in mono when the mix needs reliable translation.
Delay time versus reverb decay
Delay time is the spacing between discrete repeats. Reverb decay is the time a blended reflection field remains audible. A delay can feed a reverb to place its repeats inside a space, but the two controls are not interchangeable.
Read the reverb versus delay guide when deciding whether a part needs rhythmic repeats, continuous ambience or both.
A practical delay-sync workflow
Confirm the song BPM
Use the project tempo or measure a representative section. If the song changes tempo, one fixed delay value may not remain synchronized throughout.
Calculate the quarter-note value
Divide 60,000 by the BPM. Then choose the subdivision that fits the phrase.
Set feedback conservatively
Begin with a small number of repeats. Raise feedback only when the arrangement has enough space for a longer trail.
Filter and blend the repeats
Remove unnecessary low and high frequencies, then lower the wet level until the delay supports the source rather than competing with it.
Automate selected phrases
Send more level to the end of a line, fill or transition. This keeps the main section clear while preserving expressive repeats where they matter.
Common delay-time mistakes
Using the wrong note division
An eighth-note setting can sound very different from a dotted eighth or triplet. Check the actual repeat position against the rhythm.
Synchronizing without listening
A mathematically synced delay can still clash with a vocal phrase or drum pattern. Use the formula as a starting point and make the final decision by ear.
Leaving feedback too high
Long feedback can fill every gap and obscure the next musical event. Reduce feedback or automate it when the section becomes dense.
Forgetting tempo changes
If the song tempo changes, a fixed millisecond delay will no longer follow the same beat subdivision. Update the value or use a tempo-synced plugin.
Ignoring filtering and mono compatibility
Full-range repeats and wide offsets can create clutter or translation problems. Filter the return and check the effect on different playback systems.
Frequently asked questions
How do I calculate delay time from BPM?
Divide 60,000 by the BPM to get the quarter-note delay in milliseconds. Multiply or divide that result for half, eighth, dotted or triplet subdivisions.
What is the delay time for 120 BPM?
At 120 BPM, a quarter note is 500 ms, an eighth note is 250 ms and a dotted eighth note is 375 ms.
Is dotted eighth delay the same as eighth-note delay?
No. A dotted eighth lasts three-quarters of a quarter note, while a straight eighth lasts half of a quarter note. Their repeats fall in different rhythmic positions.
Should delay always be synced to BPM?
No. Sync is useful for rhythmic repeats, but free-time delay can create slapback, offset echoes and sound-design effects.
Why does my synced delay still sound wrong?
The selected subdivision may not fit the phrase, feedback may be too high, or the delay may be competing with reverb and other repeats. Check the rhythm, filter the return and adjust by ear.
Noah Bennett is an audio engineering writer and acoustics specialist at Reverb Calculator. He focuses on reverb time calculation, room acoustics, studio sound design, and music production tools for producers, audio engineers, musicians, and home studio creators.