Tempo and Note Length Calculator
Setting a delay or a tremolo in time with a track means converting a tempo into milliseconds, and the arithmetic is simple enough to get wrong under pressure. This gives the length of every note value at your tempo — plain, dotted and triplet — converts the tempo back from milliseconds as a check, and shows the bar length for whatever time signature you are in.
What this generator does
Turns beats per minute into milliseconds per beat, then derives every note value from a whole note down to a thirty-second, with the dotted and triplet variants of each. The tempo is converted back from milliseconds as a check.
How to use this tool
- Enter the tempo in beats per minute.
- Set how many beats are in a bar.
- Read the length of each note value.
- Use the dotted eighth figure for the classic delay setting.
Understanding the controls
- Tempo
- Beats per minute, where a beat is a quarter note — the standard convention on every sequencer and metronome.
- Beats per bar
- 4 for common time, 3 for a waltz. This only affects the bar length, not the note values.
Common use cases
- Setting a delay or reverb time in tempo with a track
- Working out note lengths for programming a sequencer
- Finding the bar length for a loop or a click track
- Converting between tempo and milliseconds while producing
- Teaching how dotted and triplet values relate to plain ones
How this generator works
A beat is sixty thousand milliseconds divided by the tempo, and a whole note is four beats. Every other value follows by halving. A dotted note is half as long again as the plain one and a triplet is two thirds, which is why three triplet eighths occupy exactly the space of two plain ones. Before display the tempo is recovered from the milliseconds and must match, every note is checked against its own fraction of a whole note, and each value is confirmed to be exactly half the one above it.
Randomness and fairness
Nothing here is random. A tempo gives exactly one set of note lengths.
For how randomness is produced across the whole site, see how Generate Random works.
Limitations and good to know
- A beat is taken as a quarter note, which is the usual convention but not universal — compound time signatures count differently.
- Swing and shuffle feels shift notes off these exact values deliberately, and no straight table describes them.
- Delay units vary in whether their time setting includes the feedback path, so the figure may need a small adjustment by ear.
- Tempo is assumed constant; a track that drifts or accelerates needs the figures recomputing per section.
Privacy and your data
The calculation runs in your browser and your tempo is never transmitted, stored or included in analytics.
Related generators
- Random Tempo GeneratorDraw a random tempo in beats per minute, with the Italian marking that covers it and how long a bar lasts at that speed.
- Tempo Ladder GeneratorThe metronome marks to work a passage up to speed, spaced so every step is the same amount harder — with the seconds per beat for each.
- Polyrhythm GeneratorTwo voices at different subdivisions, with the cycle length and the number of coinciding beats both computed from arithmetic.
- Random Drum Pattern GeneratorGenerate a drum pattern on a step grid — kick, snare and hi-hat laid out bar by bar, in simple or compound time.