Tile cost calculator for a 100 sq ft bathroom — how much tile do I need? (2026)

Tile cost calculator for a 100 sq ft bathroom

If you are asking “how much tile do I need,” start with this tile calculator and enter the floor or wall area you will actually cover. Start with the surface you are tiling, then add a waste factor and the material prices you have on hand to see quantities and costs before you order.

How much tile do I need?

Tile quantity starts with coverage, not the room’s shopping-list guess. Multiply the install area by 1 + the waste percentage, divide by the square footage of one tile, and round up to a whole piece. A 12×12 tile covers 1 sq ft, so a 100 sq ft room with 10% waste becomes 110 effective sq ft and needs 110 tiles.

• Measure the surface — use the floor area or the wall area that will actually receive tile, not the full room footprint when only a backsplash is tiled.
• Add waste — 10% is a practical starting point for a straight layout; diagonal cuts, niches, corners, and patterned layouts need more.
• Round to boxes — the calculator turns 12×12 pieces into boxes using 12 tiles per box, then rounds up so you do not order a partial carton.

Tile cost, boxes, and grout

The tile cost calculator uses the effective area for material pricing. At $2.50 per sq ft, 110 sq ft of effective 12×12 coverage is $275. That is the tile material line only: thinset, grout, trim, backer board, and labor are separate parts of a bathroom takeoff. A 12×12 porcelain box commonly holds 12 pieces, so 110 pieces rounds to 10 boxes.

Grout depends on joint width and the perimeter around each tile. Use a tighter joint for a rectified tile installation only when the tile manufacturer allows it; otherwise, keep the grout allowance conservative and buy a little extra for color matching and future repairs. The preview keeps grout optional so a quantity-first estimate does not invent a grout price.

From tile quantity to the broader material list

When the same project includes an exterior platform, use the deck calculator for decking boards, joists, and beams. If the tile is going over a new slab, the rebar calculator can size the reinforcing grid separately. Keep each material quantity tied to its own measured surface, waste factor, and packaging unit.