Variable Line Width on Grid

Have an option to have a different line width every x (and y) ammounts of lines, to more easily count large ammounts of squares.

Say, you have a 100x100 square grid and choose that every 3 squares a thicker line appears so you can easily count how many turns it would take a character to cross it.

Similar to make it easier to tell on hexagonal maps how many days it would take for the party to travel it.