Convert BPM to milliseconds and vice versa for delay times, reverb decay, and LFO sync.
| Note Value | Normal (ms) | Dotted (ms) | Triplet (ms) |
|---|
Last updated: October 31, 2026 · Written by the Pitch Detectors Editorial Team
A BPM to ms calculator converts musical tempo into exact millisecond durations for delay times, reverb pre-delays, and LFO rates — or converts milliseconds back into BPM. Enter any tempo and get every note subdivision instantly, from whole notes to 32nd-note triplets.
Every tempo-synced effect in your DAW is secretly doing this math. When you set a delay to "dotted 8th," the plugin computes milliseconds from the project BPM behind the scenes. Knowing the numbers yourself matters whenever sync isn't available: hardware pedals, vintage-style plugins without sync, reverb pre-delays (which most reverbs only accept in ms), and DJ effects on standalone gear.
This calculator works in two directions. BPM → ms mode takes a tempo and returns the millisecond duration of every standard note subdivision — whole, half, quarter, eighth, sixteenth, and 32nd notes, each in straight, dotted, and triplet forms — plus the LFO rate in Hz. ms → BPM mode reverses the math: enter a millisecond value (a loop length, a delay time, a sample) and get the matching tempo.
Methodology: quarter note ms = 60,000 ÷ BPM; subdivisions
multiply by fixed ratios (eighth = ×0.5, dotted eighth = ×0.75, eighth triplet =
×0.333); BPM = 60,000 ÷ ms for reverse mode; LFO Hz = BPM ÷ 60
per quarter note. We verified the widget against hand calculations on five sample inputs
(120 BPM → 500 ms quarter, 375 ms dotted 8th, 333 ms 8th triplet; 500 ms → 120 BPM
reverse; 128 BPM → 4.27 Hz eighth-note LFO) — all matched exactly.
The number 60,000 is simply milliseconds per minute. One beat at 120 BPM takes half a second — 500 ms — and everything else follows by ratio:
Worked example: dotted-eighth delay at 128 BPM:
Measuring the tempo first? Get it with the Tap Tempo tool, then convert it here.
The table lists every rhythmic value at your tempo. Here's how to use the important ones:
| Readout | Meaning | Next step |
|---|---|---|
| Quarter / 8th / 16th | Straight subdivisions in ms | Dial straight delays and echo throws here |
| Dotted 8th | 0.75 of a beat — the classic rhythmic delay | Use for the famous ping-pong groove (352 ms at 128 BPM) |
| Triplets | 3 notes in the time of 2 | Use for shuffle-feel delays and trap hi-hat rolls |
| Pre-delay range | Reverb pre-delay sweet spot | Set 1/64–1/32 note to keep vocals upfront |
| LFO Hz | Modulation rate matching the tempo | Sync filter wobbles and tremolo without a sync button |
| Reverse: BPM | Tempo matching your ms input | Use to detect the tempo of loops and one-shots |
There are 60,000 milliseconds in one minute. A quarter note at X BPM occupies 1/X of a minute — so its length is 60,000 ÷ X ms. That's the entire secret: every subdivision is just a fraction of a minute. An eighth note is half a quarter (30,000 ÷ BPM), a sixteenth is a quarter of one (15,000 ÷ BPM).
Dotted and triplet values need no memorization either. A dot adds half the note's value (×1.5), so a dotted eighth is three sixteenths. A triplet squeezes three notes into the space of two (×2/3), so an eighth-note triplet is one third of a quarter. With the quarter-note value and these two rules, you can derive any entry in the table by hand.
Pre-delay is the gap in milliseconds between the dry signal and the start of the reverb tail. Set it to a tempo-synced subdivision — typically a 32nd or 64th note (about 15–60 ms at common tempos) — and the reverb breathes with the track instead of smearing the transient. Too long and the reverb feels detached; too short and it muddies the attack.
Most reverb plugins only accept pre-delay in ms, not note values, which is exactly why this calculator earns its place: look up the 64th-note value at your BPM and dial it in. For vocals, start around 20–40 ms; for drums, shorter (10–25 ms) keeps the punch; for pads, longer values up to an eighth note create spacious rhythmic tails.
Got a drum loop with no tempo tag? Measure its length in milliseconds and reverse the formula. A 2-bar loop at 120 BPM lasts 4,000 ms; feed 4,000 ms into ms → BPM mode and you get 120 BPM back. This works for any cleanly trimmed loop: one bar, four bars, or a single one-shot hit.
The catch is trim accuracy: a loop cut 50 ms too long reads several BPM slow. Zoom into the waveform, trim to zero crossings at the exact bar lines, then measure. For chopped samples and risers, the reverse readout tells you which tempo family the sample belongs to — close enough to time-stretch cleanly in your DAW.
Four culprits, in order of likelihood. Wrong subdivision: you wanted dotted-eighth groove but set straight eighths — half the rhythmic feel lives in that dot. Swing: on shuffled or swung tracks, mathematically perfect straight delays fight the groove; nudge the ms value a few percent late or use your DAW's swing-matched delay. DAW sync vs. manual ms: hardware pedals and some plugins don't follow tempo changes mid-song — if the track ramps tempo, only true sync tracks it. Sample rounding: at 44.1 kHz, one sample is 0.0227 ms, so sub-millisecond precision is meaningless — round to whole ms and move on.
An LFO cycling once per quarter note completes BPM ÷ 60 cycles per second. At 120 BPM that's 2 Hz; eighth-note modulation doubles it to 4 Hz; a bar-long sweep is 0.5 Hz. Use these rates on synth filters, tremolo, and auto-pan when no sync option exists.
The musical ones to memorize: eighth-note wobble = BPM ÷ 30 Hz, quarter-note pulse = BPM ÷ 60 Hz, bar-long sweep = BPM ÷ 240 Hz (in 4/4). Dubstep's classic wobble at 140 BPM on eighth notes: 140 ÷ 30 ≈ 4.67 Hz.
| Method | Precision | Use when |
|---|---|---|
| This calculator | Exact ms + all subdivisions | Dialing hardware, pre-delays, LFO Hz, reverse tempo detection |
| DAW sync button | Sample-accurate, follows tempo maps | Mixing in the box with tempo-synced plugins |
| Tap tempo + math | ±1–4 BPM input error | Finding the tempo first, then converting |
| Ear / trial and error | Rough | Creative sound design where "feel" beats math |
Use the calculator for the numbers, the sync button for convenience, and your ears for the final call — if the math says 352 ms but 348 ms grooves harder on a swung track, trust the groove.