Tile Calculator

Estimate floor or wall tiles from area, tile size, grout gap, waste allowance and box size.

Tiles requiredTile Calculator uses the declared inputs to produce a transparent default result. Area to tile: 12 m²; Tile length: 600 mm; Tile width: 300 mm; Grout joint: 3 mm; primary comparison: 12 and 600.

Area to tilem²Tile lengthmmTile widthmmGrout jointmmWaste allowance%Tiles per boxtiles

Live math canvas

Your numbers, formula and explanation together

Tile Calculator: 933 tiles and boxes. Tile Calculator uses the declared inputs to produce a transparent default result. Area to tile: 12 m²; Tile length: 600 mm; Tile width: 300 mm; Grout joint: 3 mm; primary comparison: 12 and 600.

Formula applied

The exact method behind this answer

CalculationTime keeps the method visible so the number can be checked instead of blindly trusted.

Effective tile module area = ((tile length + grout joint) ÷ 1000) × ((tile width + grout joint) ÷ 1000). Base tiles = area ÷ module area. Tiles with waste = ceil(base tiles × (1 + waste percent ÷ 100)). Boxes = ceil(tiles with waste ÷ tiles per box).

Apply the formulaEffective tile module area = ((tile length + grout joint) ÷ 1000) × ((tile width + grout joint) ÷ 1000). Base tiles = area ÷ module area. Tiles with waste = ceil(base tiles × (1 + waste percent ÷ 100)). Boxes = ceil(tiles with waste ÷ tiles per box).933 tiles and boxesTile Calculator uses the declared inputs to produce a transparent default result. Area to tile: 12 m²; Tile length: 600 mm; Tile width: 300 mm; Grout joint: 3 mm; primary comparison: 12 and 600.

Your live breakdown

Current inputs in the calculation

These values come from the controls above and update when the calculator changes.

Area to tile: 12 m²
Tile length: 600 mm
Tile width: 300 mm
Grout joint: 3 mm
Waste allowance: 10 %
Tiles per box: 8 tiles

Resulting answer

933 tiles and boxes

Tile Calculator uses the declared inputs to produce a transparent default result. Area to tile: 12 m²; Tile length: 600 mm; Tile width: 300 mm; Grout joint: 3 mm; primary comparison: 12 and 600.

Answer: 933 tiles and boxes
Live support: Tile Calculator uses the declared inputs to produce a transparent default result. Area to tile: 12 m²; Tile length: 600 mm; Tile width: 300 mm; Grout joint: 3 mm; primary comparison: 12 and 600.

Assumptions used

What this answer assumes

Quantity estimate only. Confirm layout, batch and spare-tile needs before ordering.

Area is entered in square metres and tile dimensions are entered in millimetres.
The grout joint is treated as a layout module allowance, not as proof of actual grout volume or installation compliance.
Waste allowance covers cutting, breakage, pattern matching and spare tiles, but the right allowance depends on layout and room complexity.
The calculator rounds tile count and box count up because partial tiles and partial boxes cannot normally be purchased as exact fractions.

Master’s Tip

How to use the result well

Master’s Tip: sketch the first row and last row before ordering. A neat area calculation can still leave awkward slivers at walls, extra waste on diagonals, or a need for spare matching tiles from the same batch.

Printable record

What belongs in the saved calculation

Save the inputs, result, formula, assumptions, page URL and date together so the calculation can be reviewed later.

Area to tile: 12 m²
Tile length: 600 mm
Tile width: 300 mm
Grout joint: 3 mm

Embeddable calculator

Embed this calculator

Copy a clean iframe version with the required CalculationTime attribution link built in.

Formula

Effective tile module area = ((tile length + grout joint) ÷ 1000) × ((tile width + grout joint) ÷ 1000). Base tiles = area ÷ module area. Tiles with waste = ceil(base tiles × (1 + waste percent ÷ 100)). Boxes = ceil(tiles with waste ÷ tiles per box).

Worked example

For a 12 m² area and 600 × 300 mm tiles with a 3 mm grout joint, the module is 0.603 × 0.303 = 0.182709 m². Base tiles = 12 ÷ 0.182709 = 65.68. Add 10% waste and round up: ceil(72.25) = 73 tiles. With 8 tiles per box, ceil(73 ÷ 8) = 10 boxes.

Professional note

Regional and unit assumptions

Standard or basis: transparent metric area arithmetic using tile dimensions, grout-joint layout allowance, user-selected waste and upward rounding. This page does not certify substrate preparation, waterproofing, slip rating, grout selection or installation compliance.

Assumptions and limitations

Area is entered in square metres and tile dimensions are entered in millimetres.
The grout joint is treated as a layout module allowance, not as proof of actual grout volume or installation compliance.
Waste allowance covers cutting, breakage, pattern matching and spare tiles, but the right allowance depends on layout and room complexity.
The calculator rounds tile count and box count up because partial tiles and partial boxes cannot normally be purchased as exact fractions.

Methodology & Accuracy

How this calculator is checked

CalculationTime pages are built around visible arithmetic: the formula, assumptions, worked example and practical limitations are shown so the result can be checked rather than simply trusted.

Formula used

Standard or basis

Where a calculator follows a named legal, trade or industry standard, that standard is cited visibly. Otherwise the page uses transparent general arithmetic and states its limits.

Master's Tip

Questions

How do I calculate how many tiles I need?

Divide the tiled area by the effective area of one tile module, add a waste percentage for cuts and breakage, then round up to a whole tile count.

Should grout gaps be included in a tile calculation?

For layout planning, a small grout-joint allowance can be included in the module size. It should not be confused with a full grout-volume estimate.

How much tile waste should I allow?

A common planning range is 10% for simple layouts, with more for diagonal patterns, small rooms, many corners or pattern matching. Use the waste input to test the effect.

Why does the calculator round up to full boxes?

Tiles and boxes are discrete items. If the arithmetic says 72.25 tiles or 9.13 boxes, the practical order must round up.

Does this calculator replace a tiler or supplier check?

No. It is a transparent quantity estimate. Confirm tile batch, layout, substrate, waterproofing, trims and wastage with the supplier or installer before ordering.

Calculation note

Tile estimating is area arithmetic with practical ordering rules layered on top. The calculator makes the module size, grout allowance, waste percentage and box rounding visible so a homeowner, teacher, tiler or quote writer can file the numbers and check them later.

A tile count starts with a module, not just a tile

A tile laid with a grout joint occupies a repeated module on the surface. For quantity planning, adding the grout joint to the tile length and width gives an approximate coverage module before waste and box rounding are applied.

Waste is a layout decision

Simple rectangular rooms may need modest cutting allowance. Diagonal layouts, herringbone patterns, niches, columns, many doorways and matching grain or pattern can use more tile than the clean area suggests.

Boxes and batches matter

The final shopping quantity is normally rounded to full boxes. Keeping the box count and spare tiles visible helps avoid a second purchase from a different batch, where shade or calibre can vary.

Sources and further readingTile Council of North America: Grout FAQ Ceramic Tile Foundation: TCNA Handbook overview