Rex says
Everyday utility math — the kind you'd otherwise pull up four browser tabs for. I keep it to one clean answer.
Try a scenario
Click to load — tweak from there.Inputs
Result
Quarter note (ms)
500.0
Dotted eighth (ms)
375.0
Eighth note (ms)
250.0
Eighth triplet (ms)
166.7
Half note (ms)
1000.0
Whole note (ms)
2000.0
Psst — share this and help Rex grow
One click, a permanent link with your numbers baked in.
How to use this
- 1Enter tempo (BPM).
- 2Read your quarter note (ms) on the right — it updates as you type.
- 3Hit Share to keep the scenario or send it to someone.
About this calculator
Tempo-synced delays and reverbs sound musical because they land on rhythmic subdivisions instead of arbitrary milliseconds — a dotted-eighth delay is the classic U2/Edge sound, while a quarter-note delay is the standard slapback rhythm. This calculator converts BPM into millisecond values for straight, dotted, and triplet subdivisions from whole notes down to sixteenth notes, so you can dial in a delay pedal or plugin without doing the math by hand mid-session.
Worked example
Using the values the calculator loads with:
Inputs
- Tempo: 120 BPM
Results
- Quarter note (ms): 500
- Dotted eighth (ms): 375
- Eighth note (ms): 250
- Eighth triplet (ms): 166.7
- Half note (ms): 1,000
- Whole note (ms): 2,000
What each field means
Inputs
- Tempo (BPM)
- The tempo used in the calculation, measured in BPM. Starts at 120 BPM so you have a working example on load. Accepted range: 20–300 BPM.
Results
- Quarter note (ms)
- Returned as a decimal number and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Dotted eighth (ms)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Eighth note (ms)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Eighth triplet (ms)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Half note (ms)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Whole note (ms)
- Returned as a decimal number. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
Why is the dotted eighth note so popular for delay?
A dotted-eighth delay repeats slightly off the main rhythmic grid, creating a syncopated, cascading pattern that feels musical rather than robotic — it's the signature sound behind The Edge's guitar tone in U2 and countless ambient and pop productions since. It sits at 1.5x the straight eighth-note value.
How do I use this for reverb pre-delay or decay time?
Pre-delay is commonly set to a 16th or 32nd note value so the reverb doesn't muddy the transient of the source; decay/tail length is more genre and taste dependent but often targets an eighth or quarter note duration to stay rhythmically coherent with the track rather than washing out.
Does this work for tape echo and analog delay units too?
Yes, the millisecond math is universal — set your analog or tape delay's time knob to match the ms value for the subdivision you want, though some analog units drift slightly with temperature, so treat the calculated value as a very close starting point.
Accuracy and limitations
- Estimates assume standard, average conditions — local rules, pricing, and materials vary.
- Results are rounded for readability; add a buffer before ordering, booking, or committing.
- Double-check anything with a real cost attached against a local quote.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). BPM to Delay/Reverb Time Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/bpm-delay-reverb-time
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/bpm-delay-reverb-time" target="_blank" rel="noopener">BPM to Delay/Reverb Time Calculator — RevenueLab</a> (2026).</p>
Source: [BPM to Delay/Reverb Time Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/bpm-delay-reverb-time) (2026).