What is a note subdivision?

A subdivision divides each beat into smaller equal parts. A quarter note equals one beat; an eighth note is half a beat; a sixteenth is a quarter beat. Triplet subdivisions split the beat into three equal parts instead of two.

How is the quarter-note duration calculated?

The formula is 60,000 ÷ BPM. At 120 BPM, a quarter note lasts 60,000 ÷ 120 = 500 ms. All other values scale from there: half note = 1,000 ms, eighth note = 250 ms, and so on.

What is a dotted note?

A dotted note is 1.5× the duration of the plain note. A dotted quarter at 120 BPM = 500 × 1.5 = 750 ms. Dotted eighth = 250 × 1.5 = 375 ms.

How do I use this for delay pedal settings?

Find the subdivision you want the delay to repeat on (commonly dotted eighth for a U2-style slap delay), read off the millisecond value, and enter it into your delay pedal's time parameter.

What does the reverse converter do?

Enter a duration in milliseconds — for example, the length of an audio loop — and the calculator returns the BPM at which a quarter note matches that duration, plus all subdivisions for that tempo.

What BPM range does this support?

The slider covers 20–300 BPM, which spans slow ballads to fast drum-and-bass. You can type any value in the input field; the tool accepts 1–999 BPM.

Metronome Subdivision Calculator

Enter a BPM and get the millisecond interval for every note subdivision — quarter, eighth, sixteenth, triplets, dotted notes, and more.

Tempo (BPM)

beats per minute

20160300

Quick presets

Reverse: ms → BPM

Subdivision durations at 120 BPM

Note value

Duration (ms)

Duration (s)

Relative duration comparison

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Summary

This tool converts a tempo in BPM into precise millisecond durations for every standard note subdivision — from whole notes down to thirty-second notes, including triplets and dotted values. It also works in reverse: enter a target duration in milliseconds to find out which BPM produces that exact note length. Useful for setting delay and reverb times, programming drum machines, or simply understanding rhythmic relationships.

How it works

Enter a tempo in BPM (beats per minute) using the slider or number input.
The calculator derives the quarter-note duration: 60,000 ÷ BPM milliseconds.
All other subdivisions are computed as multiples or fractions of that base value.
Triplet values divide each beat into three equal parts; dotted values multiply by 1.5.
Use the reverse converter to paste a millisecond target and find the matching BPM.

Use cases

Set delay pedal feedback time to sync exactly with the song tempo.
Configure reverb pre-delay to a specific subdivision to avoid muddiness.
Program MIDI sequencer step lengths in a DAW that uses millisecond values.
Check whether a sampled loop matches a target BPM by measuring its duration.
Teach rhythmic subdivision relationships to students visually.
Quickly find the triplet-eighth duration when setting groove-quantize values.

Frequently Asked Questions

Last updated: 2026-06-15 · Reviewed by Nham Vu