Flooring Tile - Spacing between Ceramic Tiles

Is there a rule of thumb for the size of the space between ceramic tiles verus the size of the tiles? I am under the impression that the larger the tile, the larger the space needs to be. I have 12" x 12" tiles to install. What spacing should I be using?

There really is no rule of thumb about spacers per size of tile. My personal rule of thumb is I paid for the look of tile, not the look of grout so I usually opt for the 3/16 inch gap. It really is all personal preference. Go to a tile store that has tile laid out in different patterns and see what look you are trying to acheive and weather the gap between tiles is good for you or you would rather have something larger or smaller. Keep in mind that when you grout, the tiles will appear to be a tiny bit further apart when you are complete because the grout is close to the surface of the tile. If the tiles are slightly beveled at the surface the grout will cover this area thus making the gap look larger then when you started. Good luck.