How many tiles do I need?
- Measure the area: for a floor, length × width; for walls, the room's perimeter × height, minus doors and windows. For an L-shaped room, split it into rectangles and add them up.
- Add waste: 5–10% for cuts and breakage with a straight lay, up to 15% for diagonal or herringbone patterns. Keep a few spare tiles: if one cracks years later, the same batch will be hard to find.
- Divide by the coverage per box (printed on the label) and round up: stores do not sell half boxes.
Example · a 12 × 10 ft floor with 12 × 24 in tiles
120 sq ft + 10% = 132 sq ft. Each tile covers 2 sq ft: 132 / 2 = 66 tiles. With 16 sq ft boxes (8 tiles): 132 / 16 = 8.25 → 9 boxes. Thinset at about 50 sq ft per bag: 3 bags.
How much grout do I need?
Manufacturers use this formula, with every size in millimeters: (A + B) / (A × B) × J × T × 1.6 kg per m², where A and B are the tile's length and width, J the joint width and T the tile thickness. The smaller the tile, the more joints per square foot and the more grout you need. The calculator converts the result to pounds when you use imperial units.
Frequently asked questions
Does it work for laminate or vinyl plank flooring?
Yes for the number of boxes: enter the plank size and the coverage per box with 5–10% waste, and ignore the thinset and grout, which floating floors do not use.
And for painting?
Use the paint calculator, which works out the gallons or liters from the wall area and the number of coats.