How Many Tiles for a Bathroom Floor?

Length × width of the room gives the starting area. A typical 5×8 ft bathroom is 40 sq ft (about 1.5×2.4 m). Measure wall to wall where the tile will run, including under the vanity if the cabinet sits on the finished floor or will be installed after tiling.

The toilet footprint is usually tiled underneath the pan on a full remodel — do not subtract it unless you are leaving a cut-out around an existing flange and know the new tile stops short. Alcoves, bay windows, and step-down shower curbs should be split into rectangles and added.

Subtract only true openings you will not tile: a permanently open chase, a built-in tub deck that stays, or a different flooring threshold already set. Guessing those deductions without a sketch is how people under-order.

Convert tile size to coverage per piece. A 12×24 in tile covers 2 sq ft of face. A 6×6 in mosaic sheet might be sold by the sheet with its own coverage note — trust the box label over napkin math when sheets include joint spacing.

The Tile Calculator turns room area, tile size, and waste into a piece count and helps you avoid dividing area by tile size while forgetting grout joints and cuts. For sheeted mosaics, enter the sheet coverage the manufacturer states.

Large-format tiles on a small bathroom mean fewer grout lines but more risk of breakage and awkward cuts at the door. Plan an extra box even when the raw area math looks tidy.

Straight lay in a simple rectangle: 10% waste is a common planning band. Bathrooms with many corners, niches, or a toilet cutout often need 12–15%. Diagonal or herringbone layouts land in that higher band even in a boxy room.

Worked example: 5×8 ft floor (40 sq ft) with 12×12 in tiles. Face count before waste is 40 tiles. At 12% waste you need about 45 tiles. If the box holds 15 tiles, that is 3 boxes — buy 4 if you want a sealed spare for repairs.

UK packs often quote m² per box. Convert the room to square metres (5×8 ft ≈ 3.7 m²), add waste, then divide by m² per carton. Same logic as US boxes; different label units.

Starting from the doorway sightline usually looks better than starting from the toilet wall and ending with a sliver at the door. Dry-lay a row if you can — a half-tile at the entrance is worth adjusting the start point.

Rectified large tiles need consistent joint widths and a flatter substrate. If the floor is out of level, budget levelling compound before you blame the tile count for a bad fit.

Heated floors and membranes do not change how many tiles you need, but they do change thinset type and curing time. Follow the mat or membrane maker’s tile and adhesive guidance.

Suppliers sell by the box. Divide tile count by tiles per box (or m² per box) and always round up. Ordering “exactly enough” leaves you stranded if one tile cracks on install day.

Keep at least one unopened box after the job when the colour is hard to match. Dye lots shift. A repair three years later with a different lot shows as a patch even if the size matches.

If you are comparing material budgets, put tile, thinset, grout, and membrane lines into the Cost Estimator separately. A single “bathroom flooring” allowance hides whether waste and prep were included.

This guide is for floors. Wall tile is perimeter × height minus openings (windows, niches measured carefully). Shower walls are their own wet-area takeoff with different waste and often different tile.

If the same tile runs floor and wall, still measure each surface. Shared dye lot is good; shared area math is not. Order one combined batch only after both takeoffs are done.

For whole-house flooring comparisons (bath vs hallway vinyl, for example), the Flooring Calculator helps with broad area math, while the Tile Calculator stays better for piece-and-box tile logic.

Confirm underlayment or backer board scope. Cement board and waterproofing add cost and thickness that affect transitions at the hallway. They do not reduce tile count.

Check door clearances after the new tile height. A proud threshold can mean trimming the door — not a tile quantity issue, but a surprise if ignored.

Run final numbers through the Tile Calculator with your waste percent, round up to boxes, and stop. Extra pallets in the garage are usually the result of ordering “just in case” twice.