BPM Finder
Find the tempo of a song in beats per minute. Drop an audio file to analyze it automatically, or tap along to the beat. Check the result by playing the song with a metronome click on the detected beats.
Analyze a song
Tap tempo
Click, tap or press T on every beat. Pauses over 2 seconds start a new count.
Beat length & delay times
| Note | Straight | Dotted | Triplet | Rate |
|---|
Times for 120 BPM. Use them for delay, reverb pre-delay and LFO settings.
How to use the BPM Finder
- Choose a song: drop an audio file on the box, or press Try a demo beat.
- Read the BPM: the detected tempo appears in a few seconds with a confidence rating and other likely tempos.
- Verify it: press Play with click. If the clicks drift or fall between beats, pick another candidate or change the tempo range.
- Or tap along: tap the big button, or press T, on every beat for 8 or more beats.
- Use the numbers: copy the BPM, or read the note lengths and delay times in the table.
BPM formulas and delay times
Tempo in beats per minute and the length of one beat are two views of the same thing: beat length (ms) = 60,000 ÷ BPM and BPM = 60,000 ÷ beat length (ms). A dotted note lasts 1.5 times as long as the plain note, and a triplet note lasts 2/3 as long. At 120 BPM a quarter note is 500 ms, a dotted eighth is 375 ms and an eighth-note triplet is 166.7 ms.
| BPM | 1/4 note | 1/8 note | Dotted 1/8 | 1/16 note | One 4/4 bar |
|---|---|---|---|---|---|
| 70 | 857.1 ms | 428.6 ms | 642.9 ms | 214.3 ms | 3.429 s |
| 90 | 666.7 ms | 333.3 ms | 500 ms | 166.7 ms | 2.667 s |
| 100 | 600 ms | 300 ms | 450 ms | 150 ms | 2.4 s |
| 120 | 500 ms | 250 ms | 375 ms | 125 ms | 2 s |
| 128 | 468.8 ms | 234.4 ms | 351.6 ms | 117.2 ms | 1.875 s |
| 140 | 428.6 ms | 214.3 ms | 321.4 ms | 107.1 ms | 1.714 s |
| 174 | 344.8 ms | 172.4 ms | 258.6 ms | 86.2 ms | 1.379 s |
Tips for an accurate tempo
- Use a section with drums. Clear, regular percussion gives the strongest result. Ambient, classical or a cappella music has softer onsets, so the confidence is lower.
- Check with the click. If the clicks land between the kicks, the phase is off by half a beat but the tempo is still right; if they slowly drift, try the next candidate.
- Half or double? Count the snare: in most pop, rock and dance music it lands on beats 2 and 4. If the snare hits on every second click, the tempo is probably double what you want.
- Tap at least 8 beats and keep going; the average gets steadier with every tap. The steadiness value shows how evenly you tapped.
Frequently asked questions
How does the BPM finder detect the tempo?
It looks for moments when the sound suddenly gets louder in many frequency bands (onsets such as drum hits), measures how strongly that onset pattern repeats at every possible beat length (autocorrelation), and then fine-tunes the best beat length over the whole song to about 0.01 BPM.
Why does it show half or double the tempo I expected?
Tempo is partly a matter of feel: a drum and bass track can be counted at 174 or 87 BPM, and a slow ballad at 70 or 140. The tool prefers tempos near 120 BPM. If it picks the other one, click the half or double candidate, or choose a tempo range.
How do I calculate BPM by hand?
Count the beats for 15 seconds and multiply by 4, or count them for 30 seconds and multiply by 2. More precisely, BPM = 60 ÷ seconds per beat, so a beat every 0.5 seconds is 120 BPM.
How accurate is tap tempo?
Human taps vary by roughly 10 to 30 ms, but the error averages out. The tool fits a straight line through all your tap times, so after 16 or more steady taps the result is usually within about 1 BPM.
Does it work for songs with changing tempo?
It reports the average tempo of the whole file. For live recordings or songs with tempo changes, the confidence will be lower and the beat markers drift; trim the section you want with an audio cutter first, or use tap tempo.
What is a typical BPM for different genres?
Rough ranges: hip-hop 80 to 100, pop 100 to 130, house 120 to 130, techno 125 to 140, dubstep 140 (often felt as 70), drum and bass 160 to 180. Individual songs vary.
Is my music uploaded?
No. The file is decoded and analyzed by JavaScript in your browser, so it never leaves your device.