BPM to Milliseconds: Setting Delay and Reverb Times by the Numbers

A delay that’s set to a random number of milliseconds smears the groove. A delay locked to the tempo becomes part of it — the echoes land on the beat instead of fighting it. The bridge between “my track is 120 BPM” and “set the delay to X ms” is one short formula, and once you know it you’ll dial in tempo-synced effects in seconds.

The core formula

Tempo is beats per minute. A quarter note is one beat. So the length of a quarter note in milliseconds is:

ms per quarter note = 60,000 / BPM

There are 60,000 milliseconds in a minute, divided across the beats. At 120 BPM:

60,000 / 120 = 500 ms per quarter note

From that single value, every other note division is just multiplication:

Note value	Multiplier	At 120 BPM
Whole note	× 4	2000 ms
Half note	× 2	1000 ms
Quarter note	× 1	500 ms
Eighth note	× 0.5	250 ms
Sixteenth note	× 0.25	125 ms

Dotted and triplet delays — the secret sauce

Two divisions do most of the heavy lifting in modern production:

• Dotted eighth (× 0.75 of a quarter = 375 ms at 120 BPM). This is the classic “ambient guitar” and EDM delay. Because it lands three sixteenths apart, it weaves between your eighth-note rhythm and creates that galloping, hypnotic feel.
• Triplet eighth (× 1/3 of a quarter ≈ 167 ms at 120 BPM). Triplet delays add swing and movement without doubling the perceived tempo.

The math: a dotted note is 1.5× its base value; a triplet is 2/3 of it. The BPM to ms delay calculator prints straight, dotted and triplet values for every division at once, so you don’t have to keep a multiplier table in your head.

Using it on reverb, not just delay

The same numbers tune pre-delay and reverb decay. Setting a reverb’s pre-delay to a sixteenth note (125 ms at 120 BPM) keeps the dry transient clear before the tail blooms — vocals stay intelligible. Matching the decay time to a bar or two keeps the reverb from washing over the next phrase.

A worked example

Say you’re producing at 140 BPM and want a dotted-eighth delay on a lead synth:

1. Quarter note: 60,000 / 140 = 428.6 ms
2. Eighth note: 428.6 × 0.5 = 214.3 ms
3. Dotted eighth: 214.3 × 1.5 = 321.4 ms

Set the delay to ~321 ms (or just turn on tempo sync and pick “1/8 dotted”). Either way the echoes now reinforce the rhythm.

Beyond a single delay

If you’re building loops rather than effects, the Loop Length calculator tells you exactly how long a 1, 2, 4 or 8-bar loop runs in seconds — essential for cutting samples that loop seamlessly. And when you want your pumping sidechain to breathe in time with the kick, the Sidechain Timing calculator converts BPM into attack and release values.

Frequently asked questions

Why not just use my DAW’s tempo sync? Sync is great, but knowing the numbers lets you set hardware units, troubleshoot when a plugin’s “1/8” sounds off, and intentionally detune a delay a few ms for width.

Should delay times be exact? For a tight, modern sound, yes. For a looser, human feel, nudging a few milliseconds off-grid can add depth — but start from the correct value first.

Keep the BPM to ms calculator open on your second monitor and your time-based effects will always sit in the pocket.