Song Length Calculator
Estimate a track’s running time from its tempo, time signature and bar count — add up intro, verses and choruses to hit a target duration.
How it works
Length (s) = total bars × beats-per-bar × (60 ÷ BPM) · Convert to m:ss for the running time
A song’s length is just its total beat count spread over the tempo. Each beat lasts 60 ÷ BPM seconds, and the total number of beats is the bar count times the beats per bar. Because pop and dance arrangements are built from 8- and 16-bar phrases, thinking in phrases makes it easy to reach a target time: add or remove an 8-bar section to nudge the duration up or down by a predictable amount.
Worked example
A 128 BPM house track of 128 bars in 4/4 has 128 × 4 = 512 beats. Each beat is 60 ÷ 128 ≈ 0.469 s, so the track runs 512 × 0.469 ≈ 240 seconds — exactly 4:00. Dropping to 96 bars would bring it to 3:00.
Frequently asked questions
How many bars make a 3-minute song?
Work backwards: 3 minutes is 180 seconds. At 120 BPM in 4/4 each bar is 2 seconds, so 180 ÷ 2 = 90 bars. Faster tempos need more bars for the same duration.
Does this account for tempo changes?
No — it assumes a single steady tempo. For a track with different sections at different tempos, calculate each section separately and add the times together.
Why think in 8-bar phrases?
Most popular music groups bars into 4-, 8- and 16-bar phrases, so structural changes (a drop, a chorus, a breakdown) land on phrase boundaries. Building your arrangement in whole phrases keeps it feeling balanced and makes the length easy to control.
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This calculator is for educational purposes. Double-check important results before acting on them.