BPM ↔ Milliseconds Converter
Convert tempo between BPM and beat duration; show subdivisions and bar length.
Overview
The BPM to milliseconds converter translates tempo into the exact note durations producers need when programming delays, gating sidechains, automating LFOs, or printing tape echo. Type in a BPM and the tool returns the length of every common subdivision, from a whole note down to a 64th, including dotted and triplet variants.
Engineers reach for it constantly when dialing in tempo-synced effects on plugins that take ms rather than note values, when matching swing on hardware drum machines, or when calculating how long a bar lasts at a given tempo. Songwriters use it to plan section lengths and to translate "we need a 1.5-second tail" into a setting that locks to the groove.
How it works
The math is one line: a quarter note at any tempo lasts 60,000 / BPM milliseconds, because there are 60,000 ms in a minute and BPM counts beats per minute. From there, every subdivision is a ratio: an eighth is half a quarter, a sixteenth is a quarter of a quarter, a dotted note adds 50 percent, and a triplet divides the parent value by three (or multiplies by 2/3).
At 120 BPM that gives a 500 ms quarter, 250 ms eighth, 125 ms sixteenth, 750 ms dotted quarter, and roughly 333 ms quarter triplet. Bar length depends on the time signature: a 4/4 bar is four quarters, so 2,000 ms at 120 BPM. The converter also handles 3/4, 6/8, 5/4 and other meters by multiplying the appropriate beat unit by the count.
Examples
120 BPM → Quarter = 500 ms, 8th = 250 ms, 16th = 125 ms
90 BPM → Dotted 8th delay = 500 ms (classic slap-back)
174 BPM → 16th = ~86 ms (drum-and-bass hi-hat grid)
128 BPM 4/4 → Bar length = 1,875 ms
FAQ
Why are dotted eighth delays so popular?
A dotted eighth at moderate tempos sits between an eighth and a quarter, creating a rolling cross-rhythm against straight eighths. U2's "Where the Streets Have No Name" and countless guitar parts rely on this trick.
How do I sync a delay plugin that only takes milliseconds?
Look up the note value you want at your track's BPM and type the millisecond number directly into the plugin's time field. Disable any "host sync" toggle so it doesn't override you.
What's the difference between a triplet and a swung eighth?
A triplet divides a beat evenly into three. Swing pushes the second eighth of each pair later, somewhere between straight and triplet feel, usually expressed as a percentage.
Does this work for time signatures other than 4/4?
Yes. The note durations stay the same; only the bar length changes with the meter.