Tap tempo is the fastest way to find a song’s tempo without any audio analysis: tap a button in time with the beat and the tool works out the beats per minute. It then converts that tempo into delay times for every common note value, ready to dial into an echo or delay plugin.
How it works
Each tap is stamped with a millisecond-accurate timestamp from the browser’s performance.now() API. The tool measures the gap between consecutive taps and averages them over a rolling window of the last eight taps:
average interval = mean(tap[i] − tap[i−1])
BPM = 60000 / average interval (ms)From the BPM it derives the quarter-note delay (60000 / BPM ms) and scales it for every standard subdivision:
| Subdivision | Multiplier | At 120 BPM |
|---|---|---|
| Whole note | × 4 | 2000 ms |
| Half note | × 2 | 1000 ms |
| Quarter note | × 1 | 500 ms |
| Dotted quarter | × 1.5 | 750 ms |
| Triplet quarter | × 0.667 | 333 ms |
| Eighth note | × 0.5 | 250 ms |
| Dotted eighth | × 0.75 | 375 ms |
| Triplet eighth | × 0.333 | 167 ms |
| Sixteenth note | × 0.25 | 125 ms |
If you pause for more than two seconds the measurement resets, so a long gap between taps never corrupts the average with a massive interval.
Using delay times in practice
Audio engineers set echo and delay effects in milliseconds. A quarter-note delay at 500 ms (120 BPM) creates a single echo that lands on the next beat, which is the most basic tempo-sync effect. The dotted eighth delay (375 ms at 120 BPM) is the signature sound of many classic guitar riffs — the echo falls on the “and” of the next beat and creates a driving, syncopated feel. Triplet delays produce a shuffle or swing feel.
To set a delay pedal or plugin:
- Tap the tempo here until BPM stabilises.
- Read the delay time for the subdivision you want.
- Dial it in manually, or use the plugin’s tap tempo if it has one.
Producers and composers can use the BPM reading to confirm the tempo of a sample before warping it, to match a loop to a project, or to calculate grid-aligned timing for MIDI quantisation.
Tips for accurate readings
- Tap on the strong downbeats (beats 1, 2, 3, 4) rather than every subdivision.
- Allow six to eight taps before reading the final number — the rolling average is most stable after several intervals.
- For very slow tempos (below 60 BPM), tap on every other beat and halve the result, since very long intervals between taps are harder to subdivide consistently.
Everything runs locally in your browser — no audio is recorded or uploaded.