Song Length Calculator
Calculate a track's duration from bars, time signature, and BPM, or the bars that fit a target length.
Each bar lasts 2 seconds at this tempo and time signature.
How it works
One beat lasts 60 divided by the BPM in seconds, so at 120 BPM each beat is half a second. Multiply by the beats in a bar — four in common 4/4 time — and you know how long a single bar takes.
From there, total duration is simply bars × beats-per-bar × seconds-per-beat. Thirty-two bars of 4/4 at 120 BPM runs 64 seconds, which the tool shows as a tidy 1:04 alongside the raw seconds.
Flip it the other way and enter a target length instead — an ad slot, a loop, a fixed edit — and the tool tells you how many bars fit. Round down to keep whole bars and you've got your arrangement length.
Frequently asked questions
How do I find the length of one bar?
Multiply the beats per bar by 60 ÷ BPM. In 4/4 at 120 BPM that's 4 × 0.5 = 2 seconds per bar, so counting bars and multiplying gives the total time.
Does the time signature matter?
Yes — it sets how many beats are in each bar. A bar of 3/4 has three beats and a bar of 6/8 has six, so the same number of bars can run to very different lengths.
Why round the bar count down?
A duration rarely divides into a whole number of bars, so the raw answer often has a fraction. Rounding down keeps you to complete bars, which almost always sounds better than a bar cut short.