Flooring & Tile Calculator
Enter your room dimensions, tile size, and a waste allowance to find how many tiles to buy.
How tile quantity is calculated
Room area is length × width. Each tile's area is its length × width (converted to the same units). Dividing room area by tile area gives the exact number of tiles needed to cover the floor with no waste.
In practice you'll cut tiles to fit edges and corners, and some will break, so a waste allowance (commonly 10%, more for diagonal layouts or irregular rooms) is added before rounding up to a whole number of tiles.
Frequently asked questions
How much extra tile should I buy for waste?
10% is a common allowance for a straightforward rectangular room laid in a simple grid pattern; complex layouts, diagonal patterns, or rooms with many cuts (alcoves, bay windows) often warrant 15-20%.
Do I need to account for grout lines?
This calculator treats each tile at its stated size; for very precise ordering with large grout lines, you could add the grout width to each tile's dimensions before entering them, though it usually makes a negligible difference.
What if my room isn't a simple rectangle?
Break an irregular room into rectangular sections, calculate the area of each separately, and add them together before dividing by your tile's area.