Tempo Calculator

How does the tempo calculator work?

It divides 60,000 by the tempo. A minute holds 60,000 milliseconds and BPM counts beats per minute, so 60,000 ÷ BPM is the length of one beat. In almost all modern notation the beat is a quarter note, and every other value in the table is a fixed multiple of it.

quarter note (ms) = 60,000 ÷ BPM

• Longer and shorter notes double or halve: a half note is 2 beats, an eighth note is ½ beat, a sixteenth is ¼ beat.
• Dotted notes last 1.5 times their plain value, because the dot adds half the note again.
• Triplets last ⅔ of their plain value, because three of them fill the time of two.
• Hertz is 1,000 ÷ the length in milliseconds — the rate at which that note would repeat.
• Bar length is beats per bar × (4 ÷ beat unit) × one quarter note, so a 6/8 bar lasts three quarter notes.

The full derivation, rounding rules and test values are on the methodology page.

Worked examples at common tempos

Three tempos, three uses. Each row below is calculated with the same formula the tool uses.

A dotted-eighth value is the classic rhythmic delay setting; the delay time calculator lists every straight, dotted and triplet delay with one-click copy.

What to do with the numbers

Use them anywhere a device asks for time instead of tempo. Most plug-ins sync to the host tempo, but hardware pedals, older synths, live-sound processors and video editors often want milliseconds or hertz.

Delay and reverb

Set a delay to a note value so the repeats land on the grid, and set reverb pre-delay and decay so the tail clears before the next beat. The reverb timing calculator does the subtraction for you.

Modulation

Enter the Hz column into an LFO rate field to lock tremolo, filter sweeps or auto-pan to the tempo. Rates for whole bars are on the BPM to Hz page.

Arranging and editing

Bar length tells you how long a section lasts. To total up an intro, verse or whole song, use the bars-to-time calculator.

Practice

Hear the tempo before you play it: the online metronome opens at the same BPM when you use the “Send to” links above.

Why the time signature only changes bar length

Note lengths depend on BPM alone. A quarter note at 120 BPM lasts 500 ms whether the music is in 3/4, 4/4 or 7/8. The time signature decides how many beats fill a bar, so it changes the bar total: at 120 BPM a 3/4 bar lasts 1,500 ms and a 4/4 bar lasts 2,000 ms.

Compound meters such as 6/8 and 12/8 are counted in eighth notes but felt in dotted quarters. The calculator follows the written signature; a 6/8 bar at 120 BPM (quarter-note beat) lasts 1,500 ms. The time signature guide explains how the two numbers work.

Questions