Example 1
120 BPM and 4 -> 2.00 s per bar.
Bar length from tempo calculator
Type BPM and how many quarter notes sit in the bar. For 4/4 you type 4. At 120 BPM the barline lasts 2.00 s, or 2000 ms. In 3/4 at the same tempo it is 1.50 s. This is not the length of a whole track.
The beat alone: BPM to milliseconds. Note time: denominator in ms. Whole track: bars × tempo.
Result
Enter a value. The result shows up here.
How it works
A bar is a few quarter notes in a row. Time for one barline is 60 seconds times the quarter-note count, divided by BPM. In 4/4 you type 4. At 120 BPM: 60 × 4 / 120 = 2.00 s, 2000 ms on the second card. At 60 BPM the same bar lasts 4.00 s. At 100 BPM 2.40 s.
In 3/4 you type 3. At 120 BPM that is 1.50 s. At 90 BPM and 3 quarter notes, a common 6/8 counted to the quarter, the bar lasts 2.00 s. Six eighths are three quarters, so for 6/8 you usually type 3, not 6. If your DAW counts otherwise, type what it calls beats in the bar.
Milliseconds are seconds × 1000, rounded to whole ms. 140 BPM and 4 is 1.71 s and 1714 ms (exactly 1.714 s). 128 BPM and 4 is 1.88 s and 1875 ms. 72 BPM and 6 quarter notes is a clean 5.00 s, 5000 ms.
Both numbers must be greater than zero. This is one bar, not the whole track. For 32 barlines, multiply this result by 32 or open song length and type the bar count there. The beat alone, one quarter, lives on the BPM-to-ms page: at 120 BPM that is 500 ms, four times shorter than this bar.
Type BPM, then quarter notes, click Calculate. A comma in tempo works. The calculator does not guess score notation and does not add a pickup. A one-bar fade uses this result in seconds or in ms, depending on the automation.
Eighths and sixteenths inside the bar live on the note-duration page. The denominator of a single note is not a field here: this field means quarter notes in the barline, not “which note you are playing”.
How to use
- Type BPM, for example 120.
- Type quarter notes in the bar: 4 for 4/4, 3 for 3/4. For 6/8 at a quarter-note BPM you usually type 3.
- Click Calculate. 120 and 4 give 2.00 s and 2000 ms. 120 and 3 give 1.50 s and 1500 ms.
- For a whole track, open song length and add the bar count. This result is one barline.
- For the beat alone in ms, open beat time. At 120 BPM a quarter is 500 ms, four times shorter than a 4/4 bar.
Formula
s = (60 × quarter notes) / BPM
Milliseconds = seconds × 1000, rounded to whole ms. BPM and the quarter-note count must be greater than zero.
BPM and the length of one bar
Here bar seconds = (60 × quarter notes) / BPM. At 120 BPM and 4 in the bar the bar lasts 2.00 s, or 2000 ms. In 3/4 that is 1.50 s.
- BPM
- Tempo, how many quarter notes fit in a minute. 120 with four quarters is 2.00 s per bar. That is not the length of a whole track.
- ms
- The same bar in milliseconds: 2.00 s × 1000 = 2000. With 3 quarters at 120 BPM you get 1500 ms, not 2000.
Real-life examples
Example 2
120 BPM and 3 -> 1.50 s per barline.
Example 3
60 BPM and 4 -> 4.00 s per bar.
Example 4
140 BPM and 4 -> 1.71 s per bar.
Example 5
90 BPM and 3 -> 2.00 s in 6/8.
Example 6
128 BPM and 4 -> 1.88 s per barline.
Example 7
100 BPM and 4 -> 2.40 s per bar.
Example 8
72 BPM and 6 -> 5.00 s on a long bar.
Ways to use this calculator
- You time a fade or an automation to one bar and need that bar in seconds.
- You check whether a loop with a known bar count fits a sample slot at a given BPM.
- You compare 4/4 and 3/4 at 120 BPM: 2.00 s versus 1.50 s before you draw the grid.
Frequently asked questions
How long is a 4/4 bar at 120 and 60 BPM?
2.00 s (2000 ms) and 4.00 s (4000 ms). Formula: 60 × 4 / BPM.
How long in 3/4 at 120 BPM?
1.50 s, 1500 ms. Three quarters instead of four shorten the bar by one quarter.
How do I enter 6/8?
If BPM is a quarter-note tempo, usually 3, because six eighths = three quarters. At 90 BPM and 3 you get 2.00 s.
What do I get at 140 BPM and 4?
1.71 s and 1714 ms. Exactly 240/140 ≈ 1.714 s, ms rounded.
What about 128 BPM and 4?
1.88 s and 1875 ms. 240/128 = 1.875, 1.88 on the first card.
Is 72 BPM and 6 quarter notes 5 s?
Yes. 60 × 6 / 72 = 5.00 s, 5000 ms. A long barline, for example 6/4.
How long at 100 BPM in 4/4?
2.40 s and 2400 ms. 240/100 = 2.4, no rounding on the seconds.
Is this the whole track time?
No. This is one barline. 32 such bars at 120 in 4/4 is 64 s. That lives on song length.
Where is the quarter note alone in ms?
On the beat-time page. At 120 BPM, 500 ms. This 4/4 bar is four of those beats.
Does a comma in 128.5 work?
Yes. 128.5 and 4 give 1.87 s and 1868 ms. A comma and a period mean the same value.
Knowledge sources
Frequency and intervals in this calculator follow the hertz and A440 concert pitch.
Page updated in 2026.