How to Find the BPM of a Song: Tap Tempo Tips and Telling Double-Time from Half-Time

BPM is “how many quarter notes fit in one minute”

BPM (Beats Per Minute) tells you how many beats occur in one minute. In pop, rock, and electronic music, one quarter note is normally counted as one beat. At 120 BPM, there are 120 quarter notes per minute, so one beat lasts exactly 0.5 seconds (500 milliseconds).

The length of one beat is “60000 ÷ BPM” milliseconds. At 100 BPM that is 600 ms, at 128 BPM it is 468.75 ms, and at 150 BPM it is 400 ms. A bar of 4/4 has four beats, so at 120 BPM one bar is 2 seconds and at 128 BPM it is 1.875 seconds. Once you know the length of a beat, you can calculate delay times, video cut points, and song length.

4 ways to find a song’s BPM

There are four main ways to get a BPM. They differ in convenience and accuracy, so pick the one that fits what you need.

For songs you can’t import as a file, such as streaming tracks, live videos, or karaoke backing tracks, tapping is the easiest option. For delay time calculations or cutting video to the beat, being correct to one decimal place is enough, so with the right technique tapping gives practical accuracy.

6 tips for accurate tap tempo

Tap tempo means tapping a button at a steady interval along with the song and calculating BPM from those intervals. Human taps drift by about 10–30 milliseconds each, so the number of taps and which sound you follow make a big difference to accuracy.

1. 1

   Tap on the kick drum or snare

   Vocals and melodies push and pull against the beat, so follow the rhythm section. In four-on-the-floor music, follow the kick; in rock and pop, tap quarter notes including the snare on beats 2 and 4 (“boom, tak, boom, tak”) for a steady result.

2. 2

   Treat the first few taps as warm-up

   When you first start, your body hasn’t locked onto the tempo and timing errors are large. Listen for about two bars in a section with a steady groove, such as right before the chorus, and then start tapping.

3. 3

   Tap at least 16 times, ideally 32

   With only 4 taps, being off by several BPM is common. If each tap is off by about 20 ms, the typical error for a 128 BPM song is over ±2 with 4 taps, around ±0.5 with 8 taps, around ±0.2 with 16 taps, and under ±0.1 with 32 taps.

4. 4

   Keys are easier than the screen

   You can measure on a phone screen, but on a computer, tapping the Space or Enter key needs less finger movement and produces less timing error.

5. 5

   Don’t divide using only the first and last taps

   If you calculate “time from first tap to last tap ÷ number of intervals,” the errors in those two taps go straight into the result. Fitting a straight line through the times of all taps (least squares) averages out the errors of the taps in between, giving a more stable result from the same taps.

6. 6

   Check by layering a metronome

   Play a metronome at the BPM you measured and listen with the song for about eight bars. If the click gradually drifts ahead or falls behind, move the BPM by 0.1–1 at a time until it stays locked.

Counting with a clock, and how accurate each duration is

Even without tools, you can get the BPM by counting beats while watching a clock. The formula is “beats counted × 60 ÷ seconds counted.” 32 beats in 15 seconds is 32 × 60 ÷ 15 = 128; 25 beats in 10 seconds is 150.

With counting, the first and last beats rarely land exactly on the time boundaries, so an error of about one beat always remains. A result of 128 from a 15-second count really only means “somewhere between 124 and 132.” That is fine as a rough guide, but for delay settings or video editing, measuring to a decimal place with tapping is more reliable.

How to tell double-time from half-time

It is common to measure a BPM and find that it is exactly double or half the number in your DAW or online. This doesn’t mean you measured wrong; it is a difference in which note you felt as the beat. Dubstep at 140 BPM sounds like a relaxed 70 BPM because the snare lands only on beat 3. Conversely, hip-hop at 85 BPM can feel like 170 if you tap along with the eighth-note hi-hats.

• The count where the snare hits twice per bar (beats 2 and 4) is usually the song’s BPM
• If you counted so that the snare hits only once per bar, you are probably counting at half-time
• If you tapped along with the hi-hats, you are probably counting at double-time
• If your result is under 60 or over 200, suspect doubling or halving first
• Drum and bass is listed as both 174 and 87, and trap as both 140 and 70, so choose whichever suits your purpose

For delay and reverb settings or video cuts, using double or half still lands “on the beat.” A quarter-note delay calculated at 70 BPM is the same length as a half-note delay calculated at 140 BPM. What matters is that the BPM you enter in your DAW project matches the BPM you use for effect calculations.

Typical BPM by genre and by tempo marking

You can tell whether a measured BPM is plausible for a song by comparing it with typical ranges for its genre. The table below summarizes common ranges. Individual songs can fall outside them, so treat these as rough guides.

Tempo markings in classical sheet music also have approximate BPMs. However, the numbers vary between method books and eras, and many ranges overlap, so the table below divides them into non-overlapping ranges as a guide.

What to do with the BPM once you have it

Once you know the BPM, you can calculate many other numbers from it. It is useful not only for music production but also for video editing, dance, and choosing running music.

• Sync guitar or vocal delay to the song: a dotted-eighth delay is “60000 ÷ BPM × 0.75” (how to calculate delay time)
• Match reverb pre-delay or tremolo speed: syncing reverb and LFO to BPM
• Cut video on the beat or get the number of bars from a song’s length: bar length and song length calculations
• Match two songs’ tempos as a DJ or slow down playback for practice: playback speed and semitone calculations
• Change the key after transcribing: how to transpose chords

FAQ

What is the easiest way to find the BPM of a song?

Play the song and tap the BPM tap tool’s screen or the Space key 16 or more times along with the kick or snare. In 15–30 seconds you get the BPM to about one decimal place, along with an error estimate.

Why is the BPM slightly different every time I tap?

Each human tap is off by about 10–30 milliseconds. The fewer taps you make, the more each error affects the result. Tapping 16–32 times, following the rhythm section, and ignoring the first few taps all help stabilize the result.

My measured BPM comes out double or half. Why?

It depends on which note you felt as the beat. The count where the snare hits twice per bar (beats 2 and 4) is usually the song’s BPM; once per bar means half-time, and tapping the hi-hats means double-time. Dubstep, trap, and drum and bass are listed either way.

How accurate is counting for 15 seconds with a clock?

Because you multiply the count by 4, miscounting by one beat changes the result by ±4 BPM. Counting for 60 seconds reduces that to ±1, but for delay settings or video editing, measuring to a decimal place with tapping is more reliable.

Is 120 BPM fast or slow?

It is a medium to slightly fast tempo, common in pop and house. In tempo markings it is around the start of allegro (fast, lively). One beat is exactly 0.5 seconds, and one bar of 4/4 is 2 seconds.