I like to run some delays on 1/2 beat or 1/4 rather than on the beat
The board and/or you would need to know the BPM to work with the concept of ratio (1/2, 1/4, 1/8, etc). So take out your calculator app and do some simple math
60 000ms / BPM = 1/4 notes in ms so for example your song is 90 bpm : 60 000 / 90 = 667 ms for a 1/4 note delay
That also means that, when you tap to the beat, you already have your 1/4 note delay so you probably mean something faster like 1/8 or 1/16 note so just divide the given time on the tap delay screen by 2, 4 or 8 for 1/8, 1/16 and 1/32.