Note duration calculator
Set the tempo and what one beat is, then choose a note value. The calculator gives its length in milliseconds and seconds, how many beats it covers, how long a run of such notes takes, how many fit in a minute, the bar length for your time signature and the length in samples for audio editing.
Runs in your browser: nothing you enter is sent anywhere.
How to use
- Enter the tempo and choose which note gets the beat.
- Choose the note value and, if needed, a dot or tuplet.
- Enter how many notes you want to time and the time signature.
- Read the length of one note, of all of them and of one bar, plus the rate and the length in samples.
How it works
A whole note lasts 60 000 ÷ (tempo × beat value) ms, where the beat value is 1/4 for a quarter, 1/2 for a half, 1/8 for an eighth and 3/8 for a dotted quarter. A 1/n note is a whole note ÷ n, times the modifier: 1.5 dotted, 1.75 double-dotted, 2/3 triplet, 4/5 quintuplet. A bar of a/b lasts a × (whole note ÷ b). Repetition rate = 1000 ÷ ms in Hz, samples = seconds × sample rate.
Example
120 BPM, quarter-note beat, eighth notes, four of them, 4/4, 48 kHz:
- quarter note 60 000 ÷ 120 = 500 ms, eighth note 250 ms = 0.25 s = half a beat;
- four eighths: 1,000 ms; 240 of them fit in a minute, a rate of 4 Hz;
- one bar of 4/4: 4 × 500 = 2,000 ms;
- one eighth in samples: 0.25 × 48 000 = 12,000.
Tips
- To check a recording’s tempo, time a few bars with the tap tempo tool and compare the bar length here.
- Tempo changes the length of every note, but not the ratios between them: a dotted quarter is always three eighths.
- For a click track in odd meters like 7/8, choose the eighth note as the beat so the bar length counts every pulse.
Frequently asked questions
How long is a quarter note at 120 BPM?
At 120 beats per minute with the quarter note as the beat, each beat is 60 000 ÷ 120 = 500 ms. An eighth note is half of that, 250 ms, a sixteenth 125 ms and a whole note 2000 ms.
How do dots and triplets change the length?
A dot adds half the note's value (× 1.5), a double dot adds half and a quarter (× 1.75). A triplet fits three notes into the time of two (× 2/3) and a quintuplet five into the time of four (× 4/5). A dotted eighth at 120 BPM is 375 ms, an eighth-note triplet 166.67 ms.
What tempo do I use for 6/8?
In 6/8 the beat is usually the dotted quarter, two beats per bar. Choose 'dotted quarter' as the beat and enter the tempo you count: at 60 dotted quarters per minute an eighth note is 333.33 ms and a bar 2000 ms. If you count all six eighths, choose 'eighth note' instead.
What are the samples for?
In an audio editor you can cut loops and place events by sample number. At 48 kHz, one eighth note at 120 BPM is 0.25 s × 48 000 = 12 000 samples. For delay and reverb settings by note value, the delay time calculator lists every value at once.