Some pedals let you dial in the milliseconds for a delay. Mine don't (see the following post for the Flashback Triple Delay); I just have a dial (no indication), and/or a tap button. So I usually turn on the metronome and get the tempo I want, then tap quarter notes to that tempo. Works fine. But when someone says, set your delay to "380 milliseconds", how do I convert that to a BPM so I can tap that in?
Simple: just divide 60,000 by the milliseconds you want. So, for 380 ms,
60,000 / 380 = 159 BPM. So set the metronome to 159 and tap in quarter notes.
If you know the BPM is 159, but want that in milliseconds,
60,000 / 159 = 377 milliseconds.
Thanks to Aaron Matthies who wrote a comprehensive article at: