Re-design has it right. I have made up material lists for literally thousands of projects and the fastest, easiest way is to make a scale drawing of the pattern you want. Count the number of each tile used in the pattern, and multiply by the number of times the pattern must be repeated to cover the area to be tiled. Add 10 to 15% to the totals to account for cutting, breakage, etc.

One more thing, it is better to over-estimate the number of tiles you will need than to under-estimate. Ceramic tiles are given lot numbers when manufactured and the tiles of each type should all come from the same lot number. There is often a very distinct color/ shade variation between different lots. Most tile suppliers will accept returns of un-opened boxes, and it is always a good idea to keep a few extra tiles in case a repair needs to be made in the future.

Standard patterns have an estimated usage per sq. ft. and includes a certain amount for waste.

If it is an unstandard pattern you would do well to draw a scale drawing of the design to get an idea of how many it takes to go a couple of feet and then you can figure from that.

If you don't want to do the drawing buy a box of each size used and then lay out the pattern so you can measure usage. THen you can calculate how many it will take of each and buy a little extra.

Count the number of each tile used in the pattern, and multiply by the number of times the pattern must be repeated to cover the area to be tiled. Add 10 to 15% to the totals to account for cutting, breakage, etc.

Ceramic tiles are given lot numbers when manufactured and the tiles of each type should all come from the same lot number. There is often a very distinct color/ shade variation between different lots. Most tile suppliers will accept returns of un-opened boxes, and it is always a good idea to keep a few extra tiles in case a repair needs to be made in the future.

If it is an unstandard pattern you would do well to draw a scale drawing of the design to get an idea of how many it takes to go a couple of feet and then you can figure from that.

If you don't want to do the drawing buy a box of each size used and then lay out the pattern so you can measure usage. THen you can calculate how many it will take of each and buy a little extra.