BPM MathAbout

Song Length Calculator

Enter bars, BPM and a time signature to get the running time of a section or song, or enter a target length and see how many bars fit. The tables show common section lengths at your tempo.

64 bars run

2:08.0

128.0 seconds

One bar

2000 ms

4 beats of a quarter

Bars per minute

30.0

256 beats in total

How many bars fit a target length?

Bars in 3:30.0

105.0

105 whole bars at 120 BPM

Common section lengths at 120 BPM in 4/4

BarsLengthTypically
40:08.0Intro fill, turnaround
80:16.0Short intro, pre-chorus, bridge
160:32.0Verse or chorus
321:04.0Verse + chorus, a full loop
642:08.0A short track section, two verse-chorus pairs
963:12.0Radio-length song body
1284:16.0Full pop song at faster tempos, DJ-length intro + body

Bar = 60,000 ÷ 120 × 4 × (4 ÷ 4) = 2000 ms. Length = bars × bar.

The arithmetic

A beat lasts 60 ÷ BPM seconds. A bar has as many beats as the top number of the time signature says, in the note value the bottom number says, so a bar of 4/4 is four quarter notes, a bar of 3/4 three, and a bar of 6/8 six eighths (three quarters' worth). Song length is bars × bar length. The reverse, bars for a target time, is the target in seconds ÷ bar length, and the fractional part tells you how far into the last bar the song ends.

Song length by bars and tempo, 4/4

Bars80 BPM100 BPM120 BPM128 BPM140 BPM174 BPM
80:24.00:19.20:16.00:15.00:13.70:11.0
160:48.00:38.40:32.00:30.00:27.40:22.1
321:36.01:16.81:04.01:00.00:54.90:44.1
643:12.02:33.62:08.02:00.01:49.71:28.3
964:48.03:50.43:12.03:00.02:44.62:12.4
1286:24.05:07.24:16.04:00.03:39.42:56.6
1608:00.06:24.05:20.05:00.04:34.33:40.7

Planning an arrangement

Sections in popular music come in multiples of four bars, most often eight and sixteen, because the ear expects phrases to resolve on those boundaries. Sketch the structure in bars first, sum them, and convert once: a 100-bar pop arrangement at 116 BPM is 3:27, which is radio length, while the same 100 bars at 90 BPM run 4:27 and may want a section cut. For streaming, many producers aim for the hook inside the first 30 seconds, which at 120 BPM is bar 15, so an 8-bar intro plus a short verse gets there and a 16-bar intro does not.

Frequently Asked Questions

How do I calculate how long a song is from bars and BPM?

Seconds = bars × beats per bar × 60 ÷ BPM. In 4/4 at 120 BPM, 64 bars is 64 × 4 × 60 ÷ 120 = 128 seconds, or 2:08. The calculator does the same sum and also handles 3/4, 6/8 and odd meters, where the number of beats per bar changes.

How many bars is a 3-minute song?

Depends on the tempo. At 120 BPM in 4/4 a bar is two seconds, so three minutes is 90 bars. At 90 BPM it is 67.5 bars; at 174 BPM it is 130.5 bars. Enter your tempo in the target-length section above and the calculator gives the exact figure.

How long is a typical pop song in bars?

Roughly 90 to 110 bars of 4/4: an 8-bar intro, two 16-bar verses, two or three 8-bar choruses, an 8-bar bridge and an outro. At 100 to 120 BPM that runs 3:00 to 3:40. Dance tracks built for DJs run 128 bars or more with 16 to 32 bars of beat-only intro and outro for mixing.

What does 6/8 do to the numbers?

A bar of 6/8 has six eighth-note beats, equal to three quarter notes, so at the same quarter-note BPM it is three-quarters the length of a 4/4 bar. Many 6/8 songs are counted in dotted quarters (two per bar); if your DAW shows that tempo, double it to get the eighth-note pulse before entering it here, or just enter the DAW BPM and treat the bar count as written.

Why do I need bars per minute?

For arranging: if a track has 32 bars per minute, a 16-bar verse is 30 seconds and you can sketch a whole arrangement by minutes without a timeline. It is also how DJs judge how long a 32-bar intro gives them to mix.

These tools use the standard tempo, pitch and timing formulas (60,000 ÷ BPM, A4 = 440 Hz equal temperament, 1,200 cents per octave). They run in your browser; the tap counter uses your keyboard or mouse timing, so expect a beat or two of settling before the reading is stable.

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