Song Length and Bars-to-Time Calculator

1. Enter the tempo of the song in beats per minute.
2. Choose the beats per bar from the time signature.
3. Enter the number of bars in the song or section.
4. Read the length in minutes and seconds, plus the seconds per bar.

Song length from bars is the running time you get from a piece of music arranged as a number of bars at a set tempo. Producers and composers think in bars, but listeners and editors think in minutes and seconds, so converting between the two is a constant need.

Because tempo fixes how long each beat lasts, and the time signature fixes how many beats fill a bar, a known bar count translates directly into a precise duration, and a target duration translates back into a clean number of bars to write or program.

1. Divide 60 by the tempo for the length of one beat in seconds.
2. Multiply by the beats per bar for the length of one bar.
3. Multiply by the number of bars for the total seconds.
4. Convert seconds into minutes and seconds for a readable time.

The same formula runs in reverse: to fill a target duration, divide the total seconds by the seconds per bar to find how many bars you need.

A track runs at 120 beats per minute in four-four time and is 90 bars long. One beat is 60 divided by 120, or half a second, so a bar of four beats is two seconds. Across 90 bars that is 180 seconds, which is three minutes exactly. Speed the tempo up to 140 and the same 90 bars shorten to about two minutes and 34 seconds.

Tempo

A faster tempo shortens every bar, so the same arrangement plays quicker at a higher BPM.

Time Signature

More beats per bar make each bar longer; a bar of six-eight lasts longer than a bar of two-four at the same tempo.

Number of Bars

Length scales directly with the bar count, so adding a section adds a predictable chunk of time.

Tempo Changes

Songs that speed up or slow down need each section worked out separately, then added together.

These are common section lengths in four-four time at 120 BPM, where each bar is two seconds.

Change the tempo and every one of these scales in proportion, which is why arrangers keep a calculator close.

Arranging a Track

Check that your sections add up to a target running time before you commit.

Scoring to Picture

Work out how many bars fill a scene of a set length in film or video.

Planning a Set

Estimate how long a run of songs will last at their tempos and bar counts.

1. Ignoring the Time Signature

Assuming four beats per bar when the piece is in three or six throws the length off.

2. Forgetting Tempo Changes

A single tempo cannot describe a song that speeds up; split it into constant-tempo sections.

3. Counting Beats as Bars

A bar holds several beats, so mixing the two badly overstates or understates the length.

4. Rounding Too Early

Round only the final time; rounding seconds per bar first can drift over a long song.

The timing maths is exact for a constant tempo and a fixed time signature, so the length is precise. Real performances with tempo drift will differ slightly.

Multiply the bars by the beats per bar and by 60 divided by the tempo. At 120 BPM in four-four, 32 bars is 64 seconds.

It is the beats per bar times 60 divided by the tempo. In four-four at 120 BPM, a bar is two seconds.

At 120 BPM in four-four, a three-minute song is 90 bars, since each bar is two seconds and there are 180 seconds.

Yes. More beats per bar make each bar longer, so a six-eight bar lasts longer than a two-four bar at the same tempo.

Divide the target seconds by the seconds per bar. For a 60 second section at two seconds per bar, that is 30 bars.

Split it into constant-tempo sections, work out each length, and add them together for the total.

Length is inversely proportional to tempo, so doubling the BPM halves the running time of the same number of bars.

Yes. Enter the loop tempo, beats per bar and bar count to get its exact length in seconds for editing.

No. The calculator runs entirely in your browser and nothing you enter is stored or sent anywhere.

• Tempo in music (Wikipedia).
• Bar and measure (Wikipedia).
• Time signature (Wikipedia).