If you are willing to use offcuts to fill in spaces, mosaic-style, then 50 tiles will suffice. But you could require up to twice as many if you want a neat finish.
About 1.2 square feet x 63 tiles
You will need approximately 23.4 tiles, so 24 tiles. Assuming 13x13 tiles is in inches.
the dimensions of one tile is 13x13 inches or 1.083x1.083 feet. Therefore area of one tile is 1.1736 square feet and that of 196 tiles is 196x1.1736=230.027
Approximately 69 Square Feet.
13'x13' = 169 square feet
20
184 would do it but get 185.
16 square feet with less than one square foot of tile remaining
The best way to figure out how many 13x13 tile will be needed to cover 30 sf of floor is to calculate 13x13/144 give coverage per tile (1.1736), then take 30/1.736 = 25.56 tiles.
One 13 ft x 13 ft tile covers 169 square feet, so 2 will be enough.
6' x 9' (54 square feet) = 6 square yards of tiles needed.
56 16x16" tiles are needed.