Audio Delay Calculator
Tempo-synced delay time in milliseconds, hertz, and samples.
What it does
A tempo-synced delay repeats a sound at a musical interval rather than a fixed number of milliseconds. Once the tempo and note value are known, the delay time follows directly from the beat length.
The tool above converts BPM and a note value into milliseconds, hertz, seconds, and samples. It supports straight, dotted, and triplet feels, plus common sample rates, so the result can be typed into a plugin or a hardware delay.
At 120 BPM a quarter note lasts 500 ms. An eighth note is half of that, 250 ms, and a dotted eighth is 1.5 times the eighth, 375 ms. A triplet eighth is two thirds of 250 ms, or about 166.67 ms.
Tempo sync is a starting point, not a rule. Some productions use a slightly longer or shorter delay for groove, and some delays are not tempo-synced at all. Trust the musical result after checking the math.
How to use
- Enter the song tempo in beats per minute.
- Choose the note value you want between repeats.
- Choose straight, dotted, or triplet feel.
- Pick the sample rate used by the project or hardware.
- Read the delay in milliseconds and type it into the delay plugin.
- Use the sample count when the device asks for samples instead of time.
Formula
- BPM
- Tempo in beats per minute, with one beat equal to a quarter note.
- note value
- Rhythmic division such as 4 for quarter, 8 for eighth, or 16 for sixteenth.
- feel multiplier
- 1 for straight, 1.5 for dotted, and 2/3 for triplet.
- sample rate
- Samples per second used by the audio project or device.
The note value is the denominator of the note fraction. A quarter note is 1/4 of a whole note, so its multiplier is 4/4 = 1. An eighth note is 1/8, so its multiplier is 4/8 = 0.5.
Worked example
Example: 120 BPM, dotted eighth, 48 kHz
Tempo 120 BPM, eighth note, dotted feel, 48,000 Hz sample rate.
- Quarter note: 60,000 / 120 = 500 ms.
- Eighth note: 500 x 4 / 8 = 250 ms.
- Dotted eighth: 250 x 1.5 = 375 ms.
- Repeat rate: 1,000 / 375 = 2.667 Hz.
- Samples: 375 x 48,000 / 1,000 = 18,000 samples.
- Tool shows 375 ms, 2.667 Hz, 18,000 samples, and 0.375 s.
Reference table
| BPM | Quarter note | Dotted eighth |
|---|---|---|
| 90 | 666.67 ms | 500.00 ms |
| 100 | 600.00 ms | 450.00 ms |
| 120 | 500.00 ms | 375.00 ms |
| 128 | 468.75 ms | 351.56 ms |
| 140 | 428.57 ms | 321.43 ms |
Limits
- Assumes the beat is a quarter note, which is standard for BPM but not universal in every meter or notation style.
- Rounds the sample count to the nearest whole sample. Some devices truncate instead, which can shift very long delays by a fraction of a sample.
- Tempo-synced values do not account for latency, plugin lookahead, or host delay compensation.
- A mathematically correct delay can still sound wrong for the arrangement. Use it as a starting point, not a mandatory value.
Common mistakes
- Using 60 / BPM instead of 60,000 / BPM for milliseconds.
- Applying the dotted multiplier after converting to samples instead of before.
- Choosing a note value of 4 for an eighth note.
- Forgetting that a triplet is shorter than the straight note, not longer.
- Entering a sample rate that differs from the project or hardware rate.
Try it yourself
Quick checks. Answers sit tucked under each question.
100 BPM, quarter note, straight, 48 kHz. What is the delay?
Quarter note is 60,000 / 100 = 600 ms. That is 1.667 Hz and 28,800 samples at 48 kHz.
140 BPM, eighth note, triplet, 48 kHz. What is the delay?
Quarter note is 428.57 ms, eighth is 214.29 ms, and a triplet is two thirds of that, or 142.86 ms. That is 7 Hz and about 6,857 samples.
90 BPM, dotted quarter, 48 kHz. What is the delay?
Quarter note is 666.67 ms, and a dotted quarter is 1.5 times that, or 1,000 ms. That is 1 Hz and 48,000 samples.
Questions
How do I convert BPM to delay time?
Divide 60,000 by the BPM to get the quarter-note length in milliseconds, then multiply by the note fraction and the feel multiplier.
What is a dotted eighth delay?
It is an eighth-note delay lengthened by 50%. At 120 BPM the eighth is 250 ms, so the dotted eighth is 375 ms.
How is a triplet delay calculated?
Multiply the straight delay by two thirds. A triplet eighth at 120 BPM is 250 x 2/3 = 166.67 ms.
Why does the sample count matter?
Some hardware and plugins set delay in samples rather than milliseconds. The conversion is delay in seconds times the sample rate.
Does this calculator add reverb?
No. It only calculates delay time. Reverb needs decay, pre-delay, and room settings that are separate from tempo sync.
Should I use the exact value or adjust by ear?
Start with the exact value, then adjust if the groove needs it. Small changes can make a delay sit better with the arrangement.