About the Song Length & Bars Calculator
This calculator converts between bars, tempo and time. Enter the number of bars, the BPM and the time signature to get the exact song or section length in minutes and seconds; enter a target length to find how many bars fit; or enter bars and a target length to find the tempo you need.
It is built for producers arranging a track to a set length, composers writing to picture or a broadcast slot, DJs planning edits, worship and wedding musicians fitting a song to a ceremony, and anyone who needs to know how long a 16-bar intro or 32-bar chorus actually lasts at a given tempo.
It assumes a constant tempo with BPM counted in the beat of the time signature (quarter notes in 4/4 or 3/4). For compound meters such as 6/8 or 12/8, set the beats per bar to match how the BPM is counted: 2 or 4 if the tempo is in dotted quarters, 6 or 12 if it is in eighth notes.
How to use the song length & bars calculator
- 1Choose what to calculate: length, bars or BPM.
- 2Enter the tempo and the beats per bar (4 for 4/4).
- 3Enter the number of bars and/or the target length.
- 4Read the result and use the table to plan intros, verses and choruses.
Formula and method
BPM is the number of beats per minute, so one beat lasts 60 ÷ BPM seconds and one bar lasts beats-per-bar times that. Multiplying by the number of bars gives the total length; rearranging the same equation gives the number of bars that fit a length, or the tempo that makes a fixed number of bars fill it.
The calculation assumes the tempo is constant and that the BPM counts the same beat as the time signature. Tempo changes, fermatas, ritardandos and silence at the start or end of a recording are not included.
- BPM
- Beats per minute
- beats per bar
- Top number of the time signature (as counted at that BPM)
- s
- Length in seconds
Worked examples
64 bars at 120 BPM in 4/4
64 bars × 4 beats = 256 beats. At 120 BPM each beat is 0.5 s, so the section lasts 128 seconds = 2:08, and each bar takes 2 seconds.
How many bars in 3:30 at 100 BPM?
3 minutes 30 seconds is 210 s. At 100 BPM that is 210 × 100 ÷ 60 = 350 beats, or 87.5 bars of 4/4 — so plan 88 bars or trim half a bar.
Tempo to fit 96 bars into 3:00
96 bars of 4/4 is 384 beats. Fitting them into 180 seconds needs 384 × 60 ÷ 180 = 128 BPM.
Waltz: 48 bars of 3/4 at 90 BPM
48 bars × 3 beats = 144 beats; at 90 BPM that is 144 × 60 ÷ 90 = 96 seconds, or 1:36.
Frequently asked questions
How do I calculate song length from BPM and bars?+
Multiply bars by beats per bar to get total beats, then multiply by 60 and divide by the BPM. For example, 32 bars of 4/4 at 128 BPM = 128 beats × 60 ÷ 128 = 60 seconds.
How many bars are in a 3-minute song?+
It depends on tempo. At 120 BPM in 4/4 there are 90 bars in three minutes; at 90 BPM there are 67.5; at 140 BPM there are 105. Use the "Bars from length" mode for your tempo.
How long is one bar at 120 BPM?+
In 4/4 at 120 BPM a bar lasts exactly 2 seconds (4 beats × 0.5 s). In 3/4 it lasts 1.5 seconds. In general one bar = beats per bar × 60 ÷ BPM.
How do I handle 6/8 time?+
6/8 is usually felt in two dotted-quarter beats per bar. If your BPM is counted in dotted quarters, use 2 beats per bar; if your DAW counts eighth notes, use 6. Most DAWs display 6/8 tempo in quarter notes, which equals 3 beats per bar.
Why does my recording run longer than the calculation?+
The math covers the music at a steady tempo only. Count-ins, reverb tails, fade-outs, pauses and tempo changes add time, and streaming services also include any silence at the start and end of the file.