Tempo Finder

Need the BPM of a song for a DJ set, a workout playlist, a band rehearsal or a delay effect? Tap along to the beat, or open an audio file and let the tempo finder estimate it from the waveform. Then play the metronome at that tempo to check it lines up. Your audio never leaves your device.

Three ways to find a tempo

Audio files are decoded and analysed on your device with the browser’s Web Audio API. Nothing is uploaded.

Tempo markings

Italian tempo markings describe character as well as speed, and their BPM ranges vary between sources and metronome makers — treat these as typical ranges.

Typical tempos by style

These are common ranges rather than rules; plenty of songs sit outside them. Hip-hop at 90 BPM and drum and bass at 180 BPM share a pulse — one is exactly double the other — which is why detectors sometimes confuse half and double time.

BPM to milliseconds

Producers use these values to set delay and reverb pre-delay times so echoes fall on the beat.

Worked example

A drummer taps along to a song on the radio: 12 taps average 469 ms apart, giving 127.9 BPM with ±2% steadiness — Allegro. The tempo box fills in 128, the metronome clicks along with the chorus, and the delay table shows a dotted-eighth delay of 352 ms for the guitarist’s effects pedal. For a slow ballad file, the detector reports 144 BPM with “also plausible: 72 BPM” — the metronome makes it clear the song is really at 72.

Tips for accurate tapping

• Tap on the kick drum or the strongest beat, not on every note.
• Start tapping after the song has settled into its groove.
• Keep tapping for at least eight beats; stop and reset if you lose the beat.
• For songs that speed up or slow down, measure each section separately.
• Use the steadiness figure: under ±3% is a reliable reading.

How automatic detection works

The file is decoded to raw samples, and the detector measures how the loudness envelope rises in short windows of about 11 milliseconds — sudden rises usually mark drum hits and note onsets. It then tests every tempo from 60 to 200 BPM in half-BPM steps, checking how strongly the onsets repeat at that spacing, and reports the best match. Because a song at 70 BPM also has strong repetition at 140 BPM, the detector shows a half- or double-time alternative when one scores nearly as well. It analyses up to a minute of audio starting a fifth of the way in, skipping quiet intros.

Using BPM in practice

• DJs match tempos between tracks so beats line up during a mix.
• Runners and cyclists choose music near their cadence — for example 160–180 steps per minute.
• Musicians practise difficult passages slowly with a metronome and raise the tempo a few BPM at a time.
• Video editors cut on beats using the quarter-note duration in milliseconds.
• Producers set delay times to note values so echoes stay in time.

What’s in the template pack

• Printable tempo markings and BPM reference chart
• BPM-to-milliseconds delay chart for 60–200 BPM
• Setlist planner spreadsheet with BPM, key and song length
• Practice log with metronome targets
• Workout playlist BPM planner

The pack is a one-time download; the tempo finder is free.

Privacy

Audio files and taps are processed in your browser and never uploaded.