Station Audio

Tap tempo BPM counter

Tap the pad, or press any key, in time with the beat. The count restarts by itself if you pause for 2 seconds.

No taps yet. Keyboard: any key except Tab.

Tempo

— BPM

Tap at least twice. The reading becomes reliable after about eight taps.

Beat length at common tempos

One beat lasts 60,000 / BPM milliseconds. For every note value, dotted and triplet, use the delay time calculator.

BPMms per beatBeats per second4/4 bar length
60 1000.0 1.000 4.000 s
70 857.1 1.167 3.429 s
80 750.0 1.333 3.000 s
90 666.7 1.500 2.667 s
100 600.0 1.667 2.400 s
110 545.5 1.833 2.182 s
120 500.0 2.000 2.000 s
128 468.8 2.133 1.875 s
140 428.6 2.333 1.714 s
150 400.0 2.500 1.600 s
160 375.0 2.667 1.500 s
174 344.8 2.900 1.379 s

How to use it

Start the music, find the pulse you would clap or nod to, and tap it. On a computer, any key works (the space bar and T are the usual ones); on a phone, tap the pad. The BPM appears after the second tap and firms up as you continue. Stop for more than 2 seconds and the next tap starts a fresh count, so you can measure the next song without pressing Reset.

Only the most recent 16 taps are used. That keeps the reading responsive: if a song speeds up, the number follows within a few bars instead of being anchored to where you started.

How the tempo is calculated

Two estimates are shown. The average is the elapsed time between the first and last tap divided by the number of intervals, turned into BPM with BPM = 60,000 / interval in ms. The fitted value, shown large, comes from an ordinary least-squares line through the points (tap number, tap time); its slope is the typical interval. Because it uses every tap, not just the two at the ends, an early first tap or late final tap moves it less.

Worked example. Taps at 0, 500, 1000, 1500, 2000, 2500, 3000 and 3560 ms are perfectly steady at 500 ms except for a final tap 60 ms late. The average interval is 3560 / 7 = 508.6 ms, or 118.0 BPM. The fitted slope is 505 ms, or 118.8 BPM: closer to the true 120. The difference shrinks as you keep tapping.

The result also shows half time and double time, the milliseconds per beat, and a steadiness figure: the standard deviation of your intervals.

Where it stops being reliable

The counter measures your hands, not the recording. Human tapping typically wanders by 10 to 30 ms from tap to tap, which is why a handful of taps is not enough. Music recorded without a click (much jazz, folk, classical and older rock) often drifts by several BPM over a song, so there may be no single right answer; tap a section at a time. Rubato, fermatas and tempo changes will produce numbers that describe only the bars you tapped.

Browser timing adds a little noise of its own. Key and touch events are timestamped to within a millisecond or so on most devices, but a very busy page or a slow phone can delay them. None of this matters for the usual purpose of setting a DAW or a delay pedal to the nearest BPM.

Once you have the tempo, set it on the metronome to practise along, or look up tempo-synced delay and reverb times.

Common questions

5 answers
How many taps do I need?

Two taps give a number, but a poor one: a single interval that is 20 ms off at 120 BPM is almost 5 BPM out. By eight taps the error from ordinary tapping unsteadiness usually falls to one or two BPM, and by sixteen it is often under one. The counter uses the last sixteen taps, so keep going until the reading settles.

Why does it show half or double the tempo I expected?

Because you tapped a different pulse from the one the tempo is quoted in. Many people tap half notes in fast music or eighth notes in slow music. A drum-and-bass track is normally quoted around 170–175 BPM but often tapped at 85. Neither tap is wrong; the tempo written on a chart or in a DAW is a convention. Use the half and double figures to pick the one that matches the genre.

Does it listen to the music?

No. This page does not use your microphone or analyse audio. It only measures the time between your taps, which is why it works with music playing on any device, including a record player or a band in the room.

Why is the fitted BPM different from the average?

The average uses only the first and last tap: the total time divided by the number of intervals. The fitted value draws the best straight line through every tap and uses its slope, so a single rushed or late tap at either end moves it less. With steady tapping the two agree to a fraction of a BPM.

What does the steadiness figure mean?

It is the standard deviation of the intervals between your taps, in milliseconds. Under about 15 ms is steady tapping; above 40 ms suggests the song is changing tempo, has a loose feel, or the taps drifted. It measures your tapping as much as the music.

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