How many square feet are my 48, 4-1/4 in. long x 4-1/4 in. wide x 1/4 in. thick. tiles?

I am making photo coasters this year for Christmas and I need to figure out how much Enviro Tex Lite I need. I am have 48 tiles, each 4-1/4 in. long x 4-1/4 in. wide x 1/4 in. thick.
The Enviro Tex coverage chart:
4 oz kit= 1 sq ft
8 oz kit= 2 sq ft
16 oz kit= 4 sq ft
32 oz kit=8 sq ft
64 oz kit= 16 sq ft
1 gallon kit= 32 sq ft.

I am really terrible at math and I need to know if I have to get more Enviro Tex. I have a 4oz right now. Please help!!!