5×8 Bathroom Tile Layout Calculator

A 5×8 bathroom is 40 square feet of floor before you subtract the tub, but for ordering purposes you still tile the full footprint because the tub gets set on a mud or mortar bed rather than on tile. With 12×24 porcelain laid in a 1/3 offset you will get roughly 3 tiles across the short 5-foot wall — two full tiles and a ~12-inch cut — and 4 tiles running down the 8-foot dimension. That cut strip along one wall is the single biggest decision you will make in this room: put it against the tub apron or vanity kick where nobody sees it, never along the doorway threshold.

Plan your starting tile on a pencil line centered across the door opening. In a 5×8 the eye lands on the floor the second you walk in, so a balanced reveal at the threshold matters more than a clean cut at the back wall. Dry-lay a full row before you spread any thinset — it is cheap insurance in a space where a bad starting decision gets worse with every row.

Budget 15 percent waste on 12×24 running bond in this room, not the usual 10 percent. You have four walls on a 40-square-foot floor, which means four rows of edge cuts — that is a lot of ripping for such a small surface area. If you are using the leftover halves from one row to start the next (which you should, that is the whole point of a 1/3 offset), you can push waste down to 12 percent, but ordering the extra box protects you from lot-color mismatches if you discover a damaged tile three weeks after install.

Watch the toilet flange and the tub drain. Both create curved cuts that need a wet saw with a fine-grit blade or a hole saw — do not try to nibble them with tile nippers on porcelain. Leave a 1/4-inch gap around the flange for wax-ring compression and plan the cut so the seam between two tiles does not fall directly on the flange; a single tile with a circular cutout is always stronger than two half-tiles meeting at the drain.

If the room has a linear drain or curbless shower, rethink the 1/3 offset toward a straight-lay pattern running perpendicular to the drain — it simplifies the pitch and keeps grout lines from fighting the slope. For a standard tub install, the 1/3 running bond looks and performs great.