OneTaskBy Tim King · Updated
Tap Tempo
Space Bar, Mouse or Finger Taps, Tap Steadiness Check and Delay Times in Milliseconds
OneTask is free, with no sign-up, and built by one person.
If this tool saved you time, a coffee helps keep new ones coming.
How the Tap Tempo works
Press Play, then tap the beat on the panel or press the space bar in time with the music. Tap tempo averages your last few taps to give the BPM, shows how steady your tapping is, and converts the tempo into quarter, eighth, dotted-eighth and sixteenth note lengths in milliseconds for setting delays and LFOs. No audio is recorded or uploaded.
Tapping along is the quickest way to find the tempo of a song you can hear but cannot load into software: a band in the next room, a track on the radio, or a rhythm in your head.
How tap tempo calculates BPM
Each tap stores a timestamp from the browser's event clock, which is accurate to a fraction of a millisecond. The tool takes the time between your first and last tap in the averaging window and divides by the number of gaps between them, which gives the average beat length. Sixty thousand divided by that length in milliseconds is the tempo in beats per minute.
Averaging over eight taps smooths out the natural wobble in human tapping. Raise the number for a slow, steady song and you will get a more precise figure; lower it when the tempo changes and you want the reading to follow quickly. Pausing for more than two seconds starts a new count, so you can move on to another song without clearing anything.
Steadiness
The steadiness figure is the standard deviation of the gaps between your taps, in milliseconds. Under 10 ms is very steady; over 30 ms means the BPM is still settling and a few more taps will help.
Delay times
Delay and echo effects sound best when their repeats land on the beat. The table gives the common note values for the current tempo:
- Quarter note — one beat
- Eighth note — half a beat
- Dotted eighth — three quarters of a beat, the classic rhythmic delay
- Sixteenth note — a quarter of a beat
Type those milliseconds into a delay pedal or plugin that has no tempo sync.
If you want to keep the tempo once you have found it, set it on the metronome. To measure a recording automatically instead of tapping, the BPM detector analyses an audio file, and the rhythm tap trainer scores how accurately you tap against a click.
FAQ
How many taps do I need for an accurate BPM?
Four taps give a rough figure, and eight or more give a reading within about one BPM for most people. Steady tapping matters more than the count, so keep going until the steadiness figure drops below about 15 ms and the tempo stops changing.
Why does the tempo reset when I stop tapping?
A gap longer than two seconds is treated as the start of a new tempo. Without that, the average would blend two different songs together, or include the pause itself as one very long beat, and the result would be far too slow.
Should I tap on every beat or every other beat?
Tap on every beat you can feel, which is usually the quarter note. If you tap on every other beat the figure will be half the true tempo, and tapping on every eighth note will double it, so halve or double the result to match how the song is counted.
Does the space bar work while I am typing in a field?
No. The space bar only counts as a tap when the cursor is not inside an input or menu, so you can still edit the averaging window. Click the tapping panel, or anywhere outside the fields, and the space bar will tap again.
See also: all Audio tools, Images, Video & Screen, PDF, SVG, Simulations & Screensavers, Generative Art, Chart Makers, 3D Model Viewers, Drawing Pads, Mockups & 3D Making, Diagram Makers, 3D Science, Tracker Music.
Related tools
Metronome
Drift-free metronome with accented downbeats and WAV export.
BPM Detector
Detect the BPM of any audio file and export a click track.
Rhythm Tap Trainer
Tap along to a click and see your timing error in milliseconds.
Tuner
Tune any instrument by microphone with a live cents needle.
Scale Player
Hear any scale or mode played in any key on a keyboard.