Delay times, LFO rates, compressor release and reverb tails sit tighter in a mix when they follow the tempo. The calculator converts a tempo into note lengths in milliseconds, hertz and samples, splits a note length into reverb pre-delay and decay, turns a number of bars into a duration and works back from a delay time to the tempo.
Tap tempo: the T key or the button, several times in time; a pause of more than two seconds starts a new measurement.
| Note | Straight (ms) | Dotted (ms) | Triplet (ms) | Straight (Hz) | Straight (samples) |
|---|
Dotted notes last 1.5 times the straight value, triplets two thirds of it. Hz is the rate of a cycle with that length, for example for an LFO.
| Reverb ends after | Length (ms) | Pre-delay (ms) | Decay (ms) |
|---|
Pre-delay and decay add up to the chosen length, so the tail ends before the next note of that value. Plugins measure decay differently (RT60 or until silence), so the value is a starting point.
A quarter note lasts 60,000 ÷ BPM milliseconds, so 500 ms at 120 BPM. All other straight note values follow by doubling or halving.
Dotted = straight × 1.5, triplet = straight × 2/3, frequency in Hz = 1000 ÷ length in ms, samples = length in ms × sample rate ÷ 1000.
A bar lasts numerator × 4 ÷ denominator quarter notes; a 6/8 bar therefore equals three quarter notes.
Everything is calculated in the browser. DAWs and plugins sometimes round delay times or show them as note values; the tables list the exact values.