I am using inkscape to create a isometric tilemap. What settings do I need on the grid in document properties in inkscape to make it match up to a 64 x 32 grid in tiled?
As the link that Sidar comment alluded to, in the document properties you have the set both of the angles on the grid to 26.56 degrees. This will give you a size ratio where the height is half the size of the width.
From there, as long as all the other numbers are in pixel units and set to a value that is in the base 2 set (2, 4, 8, 16, 32, 64, etc...) you should be able to get set up a grid that matches you're requirements.