How to find the BPM of a song
To find the BPM of a song, count the beats for 15 seconds and multiply by 4. Thirty beats in 15 seconds is 120 BPM. For a closer number, tap along with the beat on a tap tempo button, or open the audio file in a BPM detector, which measures the tempo from the sound itself.
Whichever way you use, check the result by playing a click at that tempo over the song. If the clicks stay on the beat, the number is right. The BPM Key Finder does all three: it reads a file, has a tap button, and plays a click track over the song.
What BPM means
BPM stands for beats per minute, the usual unit of tempo. The librosa audio library's glossary defines tempo as "the speed of a piece of music, typically measured in beats per minute" and a beat as the regular pulse "that listeners can tap their foot to". So 60 BPM is one beat per second and 120 BPM is two.
The beat is the pulse you would clap to, not every drum hit. In 4/4 time, the beat is the quarter note, four to a bar. Fast drums such as hi-hats often play several times per beat; count those and you get two or four times the real tempo.
Method 1: count the beats yourself
- Play the song and find the pulse. Nod or tap your foot until it feels steady.
- Start a stopwatch on a beat and call that beat "zero", not "one".
- Count every beat after it until the time is up.
- Multiply by 60 divided by the seconds you counted: by 4 for 15 seconds, by 2 for 30 seconds.
Calling the first beat "zero" matters. If you call it "one", you count one beat too many, and at 15 seconds that adds 4 BPM to the answer.
The longer you count, the smaller any mistake becomes, because one missed or extra beat is multiplied by less. This is plain arithmetic:
| Count for | Multiply by | One beat off changes the BPM by |
|---|---|---|
| 10 seconds | 6 | 6 |
| 15 seconds | 4 | 4 |
| 30 seconds | 2 | 2 |
| 60 seconds | 1 | 1 |
For an exact tempo, count for a full minute or use one of the methods below.
Method 2: tap along
A tap tempo button turns your taps into a BPM. It measures the gaps between them, so you don't need a stopwatch or any counting. On the BPM Key Finder:
- Play the song in any app.
- Press the Tap button on each beat, at least 4 times. You can also focus the button and press Space or Enter.
- Keep tapping for 15 to 20 seconds. The number settles as you go.
- To start over, wait 2.5 seconds; the next tap begins a new count.
The tool works out the tempo from all your taps together, so one early or late tap doesn't throw it off much. Music software works the same way: Ableton's Live manual says of its own Tap Tempo button that "the more you tap, the more accurate the detected tempo result will be."
Tapping works without the audio file, so use it for a song you can only stream.
Method 3: let a BPM detector read the file
If you have the song as a file (MP3, WAV, M4A, FLAC and others), a detector can measure the tempo for you. The BPM Key Finder finds the moments where the sound suddenly gets louder, such as drum hits and notes starting, and checks how strongly they repeat at every tempo from 40 to 240 BPM. It gives a tempo with one decimal and an estimate of the key. The file is analysed in your browser and is not uploaded.
Detection is quick and exact on music with a steady beat. When we tested the tool on audio made with a known tempo, it found click tracks from 60 to 140 BPM within 0.01 BPM, and loops from 85 to 140 BPM, including a swung one, the same way. Real songs are harder than test audio, and we haven't measured it on a library of commercial tracks.
Music software can detect tempo too. Ableton's manual says its Auto-Warp feature "usually estimates the audio clip's tempo correctly". Streaming apps are a less reliable place to look it up: Spotify's Web API used to give a tempo in BPM for each track, but that endpoint is now marked deprecated, and since 27 November 2024 new apps can't use it.
Half-time and double-time
The most common "wrong" answer is half or double the right one. A drum and bass track at 174 BPM can be felt at 87, and a slow ballad at 70 can be counted at 140. Both counts follow the same music.
- Detectors pick one. Many lean towards tempos near 120 BPM. In the librosa library, which is widely used to analyse music, the tempo function's starting guess, start_bpm, is set to 120 by default.
- That causes real misses. In our test, a click track at 174 BPM was shown as 87, with 174 offered as the double-time. Of 24 test loops between 80 and 170 BPM, 17 got the right tempo first; for the other 7, the right tempo was in the list as the half-time, double-time or another tempo that fits.
- Software lets you switch. Ableton's manual notes the detected tempo can be twice as fast or half as slow and offers ×2 and ÷2 buttons. The BPM Key Finder shows the half-time and double-time next to the main result.
If you're not sure which to use, choose the count where your foot taps comfortably, or the one the person asking for the BPM expects.
Check the result by ear
To check a BPM, play a click at that tempo along with the song. In the BPM Key Finder, press Play with "Click on each beat" ticked. If the clicks stay on the beat to the end, the tempo is right. If they slowly drift ahead or behind, the number is a little off. If they land between beats, try the half-time or double-time.
When a song has no single BPM
Live recordings drift a little, some songs change tempo between sections, and ambient music may have almost no beat to measure. Then there is no single right answer.
For songs longer than 30 seconds, the BPM Key Finder also measures the tempo in 20-second sections, so you can see whether it stays steady. If it doesn't, give the tempo of the part you need, or tap along with that part only.
Find the BPM with the free BPM Key Finder
- Open the BPM Key Finder and choose a song, or use the Tap button while it plays.
- Read the BPM, and pick the half-time or double-time if it suits your count better.
- Press Play with the click on to check it by ear.
Your file is analysed in your browser on your own device and never uploaded.
Open the BPM Key FinderFAQ
How do you count BPM?
Start a stopwatch on a beat and call it zero, count the beats for 15 seconds, and multiply by 4. Count for 30 seconds and multiply by 2, or for a full minute, if you need a closer number.
Can I find the BPM of a song without downloading it?
Yes. Play it in any app and tap along on a tap tempo button, or count the beats for a minute. Both work for a song you can only stream.
Why do two BPM tools give different answers?
Usually one shows the half-time or double-time of the other, such as 87 and 174. Smaller gaps come from rounding, or from a song whose tempo changes, where each tool measures a different part.
Related
Sources
Each page below was read on 28 October 2026. The test figures come from CrispKit's own test on the BPM Key Finder page, run on 27 October 2026 on audio made with a known tempo and key; real songs can be harder.
- librosa, Glossary. Tempo is "the speed of a piece of music, typically measured in beats per minute (BPM)"; a beat is "a regular pulse that listeners can tap their foot to".
- librosa, librosa.feature.tempo. Estimates "the tempo (beats per minute)"; the parameter start_bpm, the "initial guess of the BPM", defaults to 120.
- Wikipedia, Tempo. Tempo is measured in beats per minute; 60 BPM "signifies one beat per second"; "in 4/4 time, the beat will be a crotchet, or quarter note".
- Ableton, Live manual: Audio Clips, Tempo and Warping. Tap Tempo: "the more you tap, the more accurate the detected tempo result will be"; Auto-Warp "usually estimates the audio clip's tempo correctly"; a detected tempo may be twice as fast or half as slow, fixed with the ×2 and ÷2 buttons.
- Spotify for Developers, Get Track's Audio Features. Marked "Deprecated"; its tempo field is "the overall estimated tempo of a track in beats per minute (BPM)".
- Spotify for Developers, Introducing some changes to our Web API (27 November 2024). New use cases can no longer access Audio Features or Audio Analysis; apps with existing extended access are not affected.
- CrispKit, BPM Key Finder: how it works and how accurate it is. Tempo searched from 40 to 240 BPM; tap tempo needs at least 4 taps and restarts after 2.5 seconds; test results for click tracks and 24 loops, run on 27 October 2026.