How do I calculate BPM?
Count the beats of a song for a while, then enter the beats and the time to get the tempo in BPM. Or enter a tempo to see how long each note lasts, for delay and reverb settings.
- Tempo
- 128
32 beats in 15 s is 128 BPM.
- Beat (quarter note)
- 468.8 ms
- Half note
- 937.5 ms
- Whole note (4/4 bar)
- 1,875 ms
- Eighth note
- 234.4 ms
- Sixteenth note
- 117.2 ms
- Dotted eighth note
- 351.6 ms
- Eighth-note triplet
- 156.3 ms
Tempo: 128. 32 beats in 15 s is 128 BPM.
How to calculate
Works out the tempo of a song in beats per minute from the beats counted in a time, or the time or beats from the tempo, and the length of each note value in milliseconds.
Example with the default inputs (Beats counted 32, Time 15 s): 32 beats in 15 s is 128 BPM.
Formula: BPM = beats × 60 ÷ seconds; one beat (a quarter note) lasts 60,000 ÷ BPM milliseconds
- The beat is a quarter note, as in 4/4 time; half a beat is an eighth note.
- A dotted note is 1.5 times its plain length; a triplet eighth is a third of a beat.
- The tempo is steady over the time counted.
Worked examples
Each example is checked against the calculator on every build.
- Beats counted 32, Time 15 s gives Tempo (BPM) 128, Beat (quarter note) 468.8 ms, Eighth note 234.4 ms, Dotted eighth note 351.6 ms.Source: SI Brochure (BIPM, 9th edition, 2019), Table 8: 1 min = 60 s
- Tempo (BPM) 120, Time 30 s gives Beats counted 60, Beat (quarter note) 500 ms, Whole note (4/4 bar) 2,000 ms, Sixteenth note 125 ms.Source: SI Brochure (BIPM, 9th edition, 2019), Table 8: 1 min = 60 s
- Beats counted 100, Tempo (BPM) 90 gives Time 66.67 s, Eighth-note triplet 222.2 ms.
How it works
Fill in any two of beats, time and tempo; the page works out the third. Beats and time must be more than 0, and the tempo, typed or worked out, must be from 1 to 1,000 BPM; otherwise there is no answer.
- Tempo (BPM) = beats × 60 ÷ seconds.
- Beats = BPM × seconds ÷ 60.
- Time (seconds) = beats × 60 ÷ BPM.
The beat is a quarter note. From the tempo, each note length in milliseconds is:
| Note | Length |
|---|---|
| Beat (quarter note) | 60,000 ÷ BPM |
| Half note | 2 beats |
| Whole note (a bar of 4/4) | 4 beats |
| Eighth note | 1/2 beat |
| Sixteenth note | 1/4 beat |
| Dotted eighth note | 3/4 beat |
| Eighth-note triplet | 1/3 beat |
The tempo and the note lengths are worked out exactly from the numbers you type (each read to 15 significant figures, the time in seconds), and show to 1 decimal place (tempo) and 0.1 ms (notes), rounded half up from the exact value: 2.0125 beats in 1 second is 120.75 BPM and shows as 120.8, and 2.01249999999999 beats shows as 120.7.
Worked examples by hand
32 beats in 15 seconds. 32 × 60 ÷ 15 = 128 BPM. One beat lasts 60,000 ÷ 128 = 468.75 ms (shown as 468.8), an eighth note 234.375 ms and a dotted eighth 351.5625 ms.
120 BPM for 30 seconds. 120 × 30 ÷ 60 = 60 beats. A beat is 60,000 ÷ 120 = 500 ms, a whole note 2,000 ms and a sixteenth note 125 ms.
100 beats at 90 BPM. 100 × 60 ÷ 90 = 66.67 seconds. A beat is 666.7 ms and an eighth-note triplet 222.2 ms.
Other questions people ask
How do I calculate BPM?
Count the beats for a set time, then multiply by 60 and divide by the seconds. 32 beats in 15 seconds is 32 × 60 ÷ 15 = 128 BPM. Counting for longer, 30 seconds or a minute, gives a steadier answer.
What is the quickest way to count?
Count the beats for 15 seconds and multiply by 4, or for 6 seconds and multiply by 10. The calculator does the same sum for any time you counted.
How many milliseconds is one beat?
Divide 60,000 by the BPM. At 120 BPM a beat lasts 60,000 ÷ 120 = 500 ms, an eighth note 250 ms and a sixteenth note 125 ms. These are common delay times for a delay effect set in time with the song.
What is a dotted eighth or a triplet?
A dotted note lasts one and a half times its plain length, so a dotted eighth is three quarters of a beat. An eighth-note triplet fits three notes in one beat, so each lasts a third of a beat.
Does this work for music not in 4/4 time?
The page takes the beat as a quarter note, as in 4/4, 3/4 and 2/4 time. In 6/8 the felt beat is often a dotted quarter; count those beats and read the tempo as dotted quarters per minute.
Can I find how many beats fit in a time?
Yes. Enter the tempo and the time, and leave the beats empty. At 120 BPM, 30 seconds hold 60 beats.