Tile Calculator
Estimate how many tiles, bags of thinset mortar, and bags of grout you need for your flooring or wall project.
On this page
Mortar and grout coverage changes with tile size, trowel notch, joint width and product. Replace the defaults with package coverage.
Tile & Thinset Measurement
Enter surface and tile dimensions, then set waste, thinset coverage, and grout coverage for the chosen layout and products.
How to Use the Tile Calculator
Tiling requires three main materials: the tile itself, the thinset mortar to stick it down, and the grout to fill the joints. Measuring accurately ensures everything matches and you don't run out of mortar halfway through.
- Measure the room: Measure the length and width of the floor or wall area you are tiling.
- Enter the tile size: Check the box for your tile dimensions. Common sizes are 12x12, 12x24, or 6x24 planks.
- Set waste and coverage: Choose a layout allowance and enter the thinset and grout coverage stated for your tile, joint, trowel, and product.
Tile Calculation Formula
We convert one tile to square feet, divide the project area by that coverage, and round up before applying the selected waste allowance.
Step 1: Convert Tile to Sq Ft
Tile Area (sq ft) = (Length in. × Width in.) ÷ 144
Step 2: Calculate Tile Count
Total Pieces = (Room Area ÷ Tile Area) × (1 + Selected Waste %)
Step 3: Calculate Mortar & Grout
Thinset Bags = Room Area ÷ Selected Thinset Coverage
Grout Bags = Room Area ÷ Selected Grout Coverage
Tile Example Calculation
You are tiling an 8-foot by 10-foot bathroom floor with 12x24 inch large-format tiles.
- Room Area: 8 × 10 = 80 sq ft.
- Tile Area: (12 × 24) ÷ 144 = 2 sq ft per tile.
- Tiles Needed: (80 ÷ 2) × 1.10 = 44 tiles total.
- Thinset example: At 70 sq ft per bag, 80 ÷ 70 = 1.14 (round up to 2 bags).
- Grout example: At 100 sq ft per bag, 80 ÷ 100 = 0.8 (round up to 1 bag).
- Related material: If you need other materials for this project, check out our Drywall Calculator.
Tips for Laying Tile
- Find the center: Dry-lay or mark reference lines before setting tile. The best starting point depends on focal lines, room shape, fixtures, and the size of edge cuts, so plan the layout before mixing mortar.
- Back-butter large tiles: If you are using tiles larger than 12x12, you should "back-butter" them. This means using the flat side of your trowel to scrape a thin layer of mortar directly onto the back of the tile before pressing it into the grooved mortar on the floor. It guarantees a 100% bond.
- Use leveling clips: If you are laying modern 12x24 or wood-look plank tiles, you must use a tile leveling system (clips and wedges). These tiles are prone to "lippage" where one corner sticks up higher than the next. The clips lock them perfectly flush.
Transparent estimate
Accuracy, assumptions, and sources
Reviewed September 29, 2026
Calculates tile count plus mortar and grout from editable product coverage values.
What this estimate assumes
- Default tile waste is 10%.
- Default thinset and grout coverage are starting values only and can be replaced with package values.
What it cannot know
- Layout, tile thickness, trowel notch, back-buttering, joint width, joint depth, and product formulation change coverage.
Reference links
Found a questionable result? Report the inputs and result so the calculation can be rechecked.
Frequently Asked Questions
How much waste should I add for tile?
Ten percent is a common starting allowance for a simple rectangular layout. Diagonal patterns, complex cuts, breakage, matching lots, and spare tiles may require more; confirm the layout before ordering.
How much does a bag of thinset cover?
A standard 50 lb bag of thinset mortar will cover about 70 to 80 square feet of floor space when using a standard 1/4" x 1/4" square-notch trowel. If using large format tiles with a larger trowel, coverage will drop to 40-50 sq ft.
Sanded vs. Unsanded Grout: Which do I need?
If the grout lines between your tiles are 1/8 inch or wider, you must use sanded grout to prevent cracking. If the grout lines are smaller than 1/8 inch (like on glass backsplashes), use unsanded grout so it doesn't scratch the tile surface.
Do I need underlayment?
Yes, you should never tile directly over plywood. You must install a cement backer board (like HardieBacker) or an uncoupling membrane (like Schluter Ditra) over the wood subfloor first.