Tile calculator

Floor or wall area plus waste, with the thinset and grout that go under and between it.

Tile

Floor or wall area plus waste, with the thinset and grout that go under and between it.

sq ft
in
WASTE
WHAT TO ORDERTile
Net area320 sq ft
Area to order352 sq ft
Tiles at 12 × 24 in176 tiles
Thinset, 50 sq ft a bag8 bags
Grout~43 lb

Diagonal and mosaic layouts waste 15 per cent. Order one full box over for future repairs.

MATERIAL COST10% WASTE

$739

352.0 sq ft of ceramic at $2.10 / sq ft

Ceramic$739
Waste share, 10%$67
All-in per sq ft$2.10

Free. No signup. The quantities carry over as line items.

How this tile calculator works

Area plus waste, and then the thinset and grout that go under and between it. The setting materials are usually forgotten and they add up fast.

The formula

area to order = area × (1 + waste) · thinset = order ÷ 50 bags · grout = order × 0.12 lb

Assumptions and defaults

Default waste10%
Diagonal or mosaic15%
Thinset coverage50 sq ft per bag
Groutabout 0.12 lb per sq ft

Pro tips

Order a full box over what you need and store it. Discontinued tile is a genuine problem three years later when a pipe leaks.

Large format needs a flat substrate more than it needs a good setter. Check the floor with a straightedge before you quote it.

Buy all your tile from one lot number. Shade variation between lots is real and it shows worst in big open floors.

Common questions

How much extra tile should I buy?

Ten per cent for a straight lay in a square room, fifteen for diagonal, herringbone or mosaic. Then one full box on top for future repairs.

How many bags of thinset do I need?

About one 50 lb bag per 50 square feet with a ¼ in notch trowel. Large format with a bigger trowel uses closer to one per 35.

How much grout for a tile job?

Roughly 0.12 lb per square foot at standard joints, which is what the calculator shows. Wide joints and small tiles both push that up sharply.

Do I need cement board under tile?

On a floor, over plywood, yes — or an uncoupling membrane. In a wet wall, always. Tile does not tolerate movement and neither does grout.

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