Music Lab
Song Length Calculator – Bars & BPM to Minutes
Bars to seconds: multiply bars × beats per bar × 60 ÷ BPM. For 48 bars of 3/4 at 145 quarter-note BPM, the duration is 59.586 seconds, displayed as 0:59.59. Add the durations of separate sections to find an album or an arrangement with tempo changes.
Common durations in 4/4
Duration in seconds = bars × 4 × 60 ÷ BPM. These values use a constant quarter-note tempo and are rounded to two decimal places. For example, 16 bars at 120 BPM last 32 seconds.
| Bars (4/4) | 90 BPM | 120 BPM | 140 BPM |
|---|---|---|---|
| 8 | 21.33 | 16 | 13.71 |
| 16 | 42.67 | 32 | 27.43 |
| 32 | 85.33 | 64 | 54.86 |
How many seconds are 48 bars of 3/4 at 145 BPM?
There are 48 × 3 = 144 beats. Each beat takes 60 ÷ 145 seconds, so 144 × 60 ÷ 145 = 59.586206… seconds. Enter 145 BPM, 3 beats per bar and 48 bars. The rounded clock result is 0:59.59.
| Bars | Beats/bar | BPM | Seconds |
|---|---|---|---|
| 48 | 3 | 145 | 59.586 |
| 64 | 4 | 120 | 128 |
| 16 | 3 | 90 | 32 |
| 32 | 6 | 120 | 96 |
| 1 | 4 | 60 | 4 |
How do I calculate album length or tempo changes?
Calculate each track or section separately and add the unrounded seconds. A section of 16 bars in 4/4 at 120 BPM takes 32 seconds; another of 8 bars in 3/4 at 90 BPM takes 16 seconds. Together they last 48 seconds. Add only gaps, tails or pauses actually present in the recording. This tool does not measure audio files.
In 6/8, six eighth-note beats per bar at 120 eighth-note BPM equal two dotted-quarter beats at 40 BPM. Keep the two pulse conventions separate.
Check your pulse with the metronome and use the delay calculator for individual note values.
How do bars and beats become minutes?
A bar groups a chosen number of beats. BPM describes how many of those beats occur in one minute. Multiplying bars by beats per bar gives the total beat count; multiplying by 60 and dividing by BPM converts that count to seconds. Keep the beat unit consistent in both inputs.
How long is an 8-bar or 64-bar section?
At 120 BPM in 4/4, eight bars last 8 × 4 × 60 ÷ 120 = 16 seconds. A 64-bar arrangement lasts 64 × 4 × 60 ÷ 120 = 128 seconds, shown as 2:08. Two sections with the same tempo can be added by adding their bar counts.
How does a different time signature change the result?
Sixteen bars in 3/4 at 90 quarter-note BPM last 16 × 3 × 60 ÷ 90 = 32 seconds. For 6/8, use six eighth-note beats or two dotted-quarter beats, depending on how the BPM is counted. The denominator alone does not tell you which pulse the performer is counting.
What should I count before calculating?
Count whole bars in the section, identify the pulse used by the tempo marking and enter that pulse count as beats per bar. Calculate sections with different tempi separately. A pickup, a fermata, an uncounted pause or a reverb tail needs a separate timing allowance. The calculator does not analyse audio.
For note-level effect timing, use the BPM to ms delay calculator.
Frequently asked questions
How do I calculate song length from bars and BPM?
Multiply the number of bars by the beats per bar, then multiply by 60 and divide by BPM. The result is seconds. Divide by 60 for minutes, or use the calculator’s minutes-and-seconds display. The BPM and beats-per-bar values must refer to the same beat unit.
How long are 8, 16 and 32 bars at 120 BPM?
In 4/4 at 120 BPM, each bar lasts two seconds. Eight bars last 16 seconds, 16 bars last 32 seconds and 32 bars last 64 seconds. These durations change when the tempo or beats per bar changes; bar count alone does not determine a song’s length.
Can I calculate a song in 3/4 or 6/8?
Yes. Enter three beats per bar for 3/4 when BPM counts quarter notes. For 6/8, enter six if BPM counts eighth notes, or two if BPM counts dotted-quarter beats. Use the same beat unit in both inputs; entering six against dotted-quarter BPM would triple the calculated duration.
What if the song changes tempo or includes a pickup?
Calculate each section with its own tempo and beats per bar, then add the section durations. This calculator accepts whole bars, so calculate a partial pickup separately using beats × 60 ÷ BPM. Pauses, fermatas, free timing and audio tails may make the recording longer than the calculated arrangement.
Formula and worked examples checked by DelGlorio Records on 7 October 2026. Values are calculated from the inputs and beat-unit assumptions shown above.
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