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Time Signature: What the Top and Bottom Numbers Mean

In a time signature the top number counts the beats in one bar, and the bottom number names the note that takes one beat. Two over 4 means two quarter-note beats; six over 8 means six eighth notes, grouped as two dotted-quarter beats. This page is the hub for every meter on the site: the chart below gives each common meter its beat, the length of one bar at a chosen tempo and a link to the page that counts it. Below that: simple against compound meter, and a step-by-step way to work out the meter of a song you can already play.

The two numbers, read one at a time

The lower number is not a fraction, and it is not the number of beats. It is a code for one note value: 2 stands for a half note, 4 for a quarter note, 8 for an eighth note and 16 for a sixteenth. The upper number then says how many of that note fill the bar. That is why 3/4 is read as “three four” or “three quarter time”, never as three quarters of anything.

What each lower number means
Lower number One beat is Example
2 A half note 2/2, written as a crossed C
4 A quarter note 4 4, 2/4, 3/4
8 An eighth note 6/8, 9/8, 12/8
16 A sixteenth note Rare, and usually fast on paper only

When the lower number is 4 and the upper number is 4, the meter is plain 4 4 time, and printed music usually shows it as a letter C — the symbol covered on the common time page.

Common time signatures in one chart

Every row below is a meter you will meet on an ordinary gig or in an ordinary practice room. The bar length is given at one fixed reference speed so the rows can be compared with each other; the converter underneath rebuilds the same table at any tempo you type. The last column points at the page that counts the meter properly.

Common meters, their beat and the length of one bar at 120 quarter notes a minute
Meter Beats in a bar One beat is Bar length Bars a minute Read more
4 4 (common time) 4 Quarter note 2 seconds 30 Count four beats
2/4 2 Quarter note 1 second 60 Two-beat marches
3/4 3 Quarter note 1.5 seconds 40 3/4 against 6/8
6/8 2 Dotted quarter note 1.5 seconds 40 Six eighths in two groups
9/8 3 Dotted quarter note 2.3 seconds 26.7 How compound meter works
12/8 4 Dotted quarter note 3 seconds 20 Four dotted beats a bar
2/2 (cut time) 2 Half note 2 seconds 30 Cut time, counted in two
5/4 5 Quarter note 2.5 seconds 24 Five beats, grouped 3+2

12/8 has no page of its own on this site yet; the compound meter page carries it inside the dotted-beat family. A meter that is not on the chart is not forbidden — it is simply not common enough to earn a row here.

The same meters at your tempo

Type the quarter-note speed you are working at. The rows rebuild from that one number, which is how a click track and a written score stay in agreement.

Bar length and bars a minute at 120 quarter notes
Meter Bar length Bars a minute
4 4 2 seconds 30
2/4 1 second 60
3/4 1.5 seconds 40
6/8 1.5 seconds 40
9/8 2.3 seconds 26.7
12/8 3 seconds 20
2/2 2 seconds 30
5/4 2.5 seconds 24

Try 90 in place of 120: the 4 4 bar becomes 2.7 seconds and the 6/8 bar 2 seconds, so the dotted beat still fills the shorter bar.

Simple meter splits in two, compound splits in three

Take one beat and divide it. If it breaks into two equal parts, the meter is simple. If it breaks into three, the meter is compound. That single test sorts most meters without any counting: 2/4, 3/4 and 4 4 are simple, because their quarter-note beat becomes two eighths. 6/8, 9/8 and 12/8 are compound, because their dotted-quarter beat becomes three.

  1. 1beat
  2. +eighth
  3. +eighth
  4. +eighth

One compound beat: the dotted quarter, counted “1 la le”. A simple beat would show two columns here, not three.

The top number gives you a shortcut: a multiple of 3 — 6, 9 or 12 — is almost always compound, while 3 itself is not, because three quarter notes in 3/4 are three separate beats. Five is not a multiple of 3 at all, which is why 5/4 is an odd simple meter rather than a compound one, even though playing five beats feels unusual at first.

Reading a song's meter, step by step

This is the part most guides skip: not the definition of a meter, but the order of operations for finding the meter of a recording in front of you.

  1. Run the recording through the audio analyzer or tap along with it on tap tempo and write down the tempo. That number is the beat rate, and it is all our tools will give you.
  2. Find the pulse you would tap with one foot. It should be the rate you already have, or half or double it.
  3. Count that pulse in groups of two, three or four, and restart at one each time until the song's accents line up with your restart. The size of the group is your top number.
  4. Listen inside one beat. Two even subdivisions means the lower number is 4 (or 2); three even subdivisions means the lower number is 8 and the meter is compound.
  5. Read the pair off the chart above and open the page for that meter to check your reading against a counted example.

Two honest limits. First, the analyzer returns a tempo only; it never prints a meter, and no setting will make it do so. Second, a song can change meter partway — a three-beat bar in the middle of a four-beat song is a real thing, and the group count is what catches it.

Tools on this site and what they answer

Audio analyzer: gives tempo and key from a file, never a meter. Tap tempo: gives the beat rate you tap. BPM to ms: turns a tempo into the length of one beat, useful when you already know the beat and want the milliseconds. BPM guide: what that tempo number is counting. None of them decides whether a bar holds three beats or four; that judgement stays with your ears, using the steps above.

Time signature: quick answers

What is a time signature?

Two stacked numbers at the start of a piece that fix how many beats a bar holds and which note value counts as one beat.

Which numbers are on top and bottom?

Top: the count of beats per bar. Bottom: a code for the beat's note value, where 2 is a half note, 4 a quarter, 8 an eighth.

What is the most common time signature?

4 4, also called common time. Its bar holds four quarter notes, and it is the default in pop, rock and most dance music.

How do I find the time signature of a song?

Get the tempo first, tap the beat, group the taps in twos, threes or fours until the accents line up, then check whether each beat splits in two or in three.

Is 3/4 read as three fourths?

No. Say three four, or three quarter time: three quarter-note beats in the bar.

Does the time signature set the speed?

No. Two pieces in 4 4 can sit at completely different tempos. Speed comes from the tempo marking, not the meter.

What this hub does not do