@kwt7667 asked me to repost this chart that I had posted some time back. I made this as a study guide for myself a couple years ago when I was first learning the fretboard. It’s for a 5 string with 21 frets, which is what I was playing at the time, but it can be adapted to a 4 string. The white cells represent the white keys on a piano (naturals), while the black cells represent the black keys (sharps and flats). It was a great learning tool for me to understand the logic of the fretboard and how it relates to the piano keyboard.
It doesn’t hurt to post it again if it helps more people.
P.S. I know the 1st column under zero should be white keys, but I can’t find my original Photoshop file to fix it. Sorry 'bout that.