How much floor tile for a room?
Short answer
Floor area plus 15% waste for cuts and breakage, more for a diagonal or herringbone layout. Buy every box from the same lot. Thinset and grout coverage is printed on the bag.
This is one task. Get the whole renovation in the right order.
Enter your rooms once: every task, materials for each, what you save doing it yourself, and where you must call a pro.