Tile Calculator

How many tiles do I need?

This tile calculator estimates how many tiles and boxes you need for a floor or wall. Enter the area dimensions, tile size, grout joint width, and package quantity. The tool calculates the surface area, compares an area-based tile count with a simple row-and-column layout estimate, adds your selected waste allowance, and rounds the result up to full boxes. It works for room floors, bathroom walls, kitchen backsplashes, shower surrounds, and other rectangular surfaces.

Choose a rectangular room or enter an area you already know. If you have several rooms or wall sections with the same measurements, set the matching section count. Enter tile length and width as printed on the box, the grout joint planned for installation, and the number of tiles in each box. You can also estimate material cost by entering a price per box.

The number is an ordering estimate, not a final tile layout drawing. A real project may need extra pieces for cuts around doors, pipes, cabinets, niches, corners, and patterns. Keep a few spare tiles for future repairs when the product may be discontinued or the dye lot may change.

How to use this floor and wall tile calculator

Select Imperial or Metric measurements. Imperial room sizes use feet, tile dimensions and grout width use inches, and known area uses square feet. Metric room dimensions use metres, tile sizes and grout use millimetres, and known area uses square metres. When you switch units, the calculator converts the current entries so they continue to represent the same physical dimensions.

For a rectangular room, measure the length and width of the surface to tile. For an irregular space, break it into rectangles and calculate each separately, or enter the total area if you have measured it. Count repeated rooms only when their area and layout are the same. For walls, measure each wall section that will receive tile and do not include doors or windows if you have subtracted them from your area.

Enter the actual tile face dimensions, not the box dimensions. Tile labels may list nominal dimensions, which can differ slightly from actual manufacturing size. Enter the grout width used in your layout. The calculator estimates a module layout using tile size plus grout joint and checks both tile orientations for rectangular areas. For known area, it uses tile face area because room length and width are not available for row counts.

Enter the number of tiles per box from the package label. The calculator applies waste to the estimated tile count and rounds boxes up to whole packages. If you enter a box price, it multiplies the required box count by that price. Confirm the tile coverage per box with the label because pack counts and tile sizes vary.

Tile quantity formula

The area method divides the total surface area by the face area of one tile. The layout method estimates rows and columns using the tile's dimensions plus grout width, then checks the rotated orientation. The calculator uses the larger of those estimates as a practical base count before adding waste. This helps avoid an unrealistically low quantity when a surface has many partial edge rows, though a detailed cutting plan can still change the result.

• Rectangular surface area = length × width × number of matching surfaces
• Tile face area = tile length × tile width
• Area-based count = surface area ÷ tile face area
• Module spacing = tile dimension + grout joint
• Order count = base tile count × (1 + waste allowance)
• Boxes required = order tile count ÷ tiles per box, rounded up

Worked example: tile a 10 by 12 room

Suppose a room is 10 feet by 12 feet, and you plan to install 12 inch by 12 inch tiles with a 1/8 inch grout joint. The floor area is 120 square feet. Each tile covers 1 square foot before grout spacing, so an area-only estimate starts at 120 tiles. The simple module layout is about 10 tiles across and 12 rows long, which also gives 120 tiles before edge cuts and waste.

If you add a 10 percent waste allowance, the estimated order is 132 tiles. If each box contains 10 tiles, you need 14 boxes because the box count rounds up. The extra tiles cover some cuts, breakage, and layout adjustments, but a complex pattern or room with many alcoves may need more. Check the manufacturer’s stated coverage and an installer’s layout plan before placing a large order.

A diagonal pattern changes the number of cuts at walls and may increase waste. A room with several doorways or closets may also need more planning than a simple rectangle. The calculator gives a useful starting quantity, while a scaled tile layout helps refine cuts and decide where to place full tiles.

Tile size, grout width, and coverage

Tile size affects both the number of pieces and the layout. Larger tiles cover more area per piece but may create more challenging cuts in a small room. Small mosaic sheets contain many individual pieces but are sold by sheet or box. For mosaics, use the coverage per sheet or box rather than treating every small square as a separately purchased tile unless the package is priced that way.

Grout width is the space between neighboring tiles. It affects the repeating module dimensions and the visual pattern. The calculator includes grout width in its row-and-column estimate, but grout does not subtract tile material area from the room in the same way as a geometric tile face measurement. It is used as spacing between pieces. Follow the tile manufacturer’s recommendation for joint size and installation method.

Tile boxes often show both piece count and coverage. Coverage may account for the product's nominal dimensions and intended grout joint. If the label provides reliable square footage or square metres per box, compare it with the calculator's result and follow the more appropriate product-specific quantity. Keep the same unit system while comparing coverage numbers.

Tile waste and extra pieces

Waste allowance gives you extra pieces beyond the basic area and layout count. It can cover cuts at edges, breakage during handling, small measurement errors, and pieces rejected for defects. A straightforward room with a straight pattern may need less spare tile than a diagonal or herringbone layout with many angled cuts. Stone and handmade tiles may have more variation than factory-made ceramic tile.

There is no single waste percentage that fits every job. Use the installer’s recommendation, the tile supplier's guidance, and the complexity of the plan. The tool lets you enter a percentage and rounds the result to full tiles and boxes. Avoid ordering too little for a product that may be difficult to match later, but also check the return policy for unopened boxes before ordering a large surplus.

If you keep spare tiles after installation, store them in a dry, safe place with the product name, size, color, and lot information. A matching spare can be valuable if a tile cracks years later. Keep a few from the original batch because later production may have a slight color or finish difference.

Tile calculator for bathroom, shower, and kitchen projects

For a bathroom floor, measure the finished floor area and subtract large openings or areas that will not be tiled. Tile around toilets, vanities, and floor drains requires cuts, so plan the layout before estimating final quantities. A small room can use a surprisingly large number of cuts even when its area is easy to calculate.

For shower walls and tub surrounds, calculate each wall as its own rectangle, then add the wall areas. Subtract windows or large niches if you have measured them accurately, but allow material for returns, shelves, curb faces, and other tiled details. Waterproofing, substrate preparation, trim, and setting materials are separate from tile count. Follow the shower system and tile product installation instructions.

For a kitchen backsplash, measure the length and height of each tiled run and account for outlets, windows, and cabinets. Small interruptions can create extra cuts even if their area is modest. Decide where the pattern begins and ends so visible cuts fall in suitable locations. This calculator estimates quantity; it does not design the layout around outlets or cabinetry.

Tile patterns and room layout

A straight grid pattern aligns tile edges with room walls and is often the simplest layout to estimate. A running bond offsets each row. Diagonal layouts turn the grid and commonly create more edge cuts. Herringbone, basket weave, and other patterns may use multiple tile sizes or repeat units. The calculator's row-and-column estimate is best suited to a basic rectangular grid; use a detailed layout for specialty patterns.

Before installation, dry lay a few rows or make a scaled plan. Check the size of the cut pieces along opposing walls and shift the layout if needed to avoid very narrow slivers. Consider door thresholds, transitions to other flooring, focal points, and the location of grout lines. A balanced layout may use a slightly different quantity than a simple area estimate.

Large-format tile may need a flatter substrate and a specific setting method. Tile thickness and transition height can affect nearby flooring and door clearance. These installation details do not change the basic area formula, but they are important when selecting and planning the material.

Boxes, cost, and ordering tile

The box estimate divides the order tile count by the number of pieces in one box and rounds up. A box price can be entered to estimate the tile material subtotal. If the supplier prices by area rather than by box, compare the coverage per box and calculate the appropriate number of packages. Keep all figures in the same currency and unit system.

Tile cost is only part of a completed project. Underlayment, backer board, waterproofing, thinset, grout, spacers, edge trim, sealant, tools, delivery, labor, and disposal may be separate costs. Some tile types also need special cutting blades, handling, or installation methods. Ask for a complete quote when preparing a project budget.

Check stock availability and dye lot before ordering. If more tile is needed later, a different lot may have a visible shade variation. For a large project, confirm the delivered boxes match the selected product and inspect them for damage before installation. Store cartons flat and follow manufacturer handling directions.

Common tile measurement mistakes

A common mistake is measuring wall-to-wall without accounting for areas that will not be tiled, or forgetting returns and small wall sections that will. Another is confusing tile size with box coverage. The size of one tile is not the same as the number of square feet covered by a box. Enter the piece count per box and tile dimensions in their own fields.

Room dimensions should describe the actual finished surface. A room may not be perfectly square, so measure both ends of each wall and note any changes. For an irregular room, split it into rectangles rather than relying on one average length and width. Measure wall height from the intended tile start to the finish line, not necessarily from the floor framing.

Finally, remember that a quantity estimate does not replace a cutting plan. Different patterns, borders, diagonal edges, and repeated motifs affect how many cuts can be reused. Check the box coverage and get an installer’s input for expensive tile or a complex pattern.

Limits of an online tile calculator

This tool estimates pieces and boxes from surface area, tile dimensions, grout spacing, and waste allowance. It does not create a measured installation drawing, calculate thinset or grout volume, evaluate substrate flatness, design waterproofing, or confirm a product is suitable for a wet or exterior location. The diagram is a simplified visual guide and is not drawn to scale.

Confirm measurements on site and follow the tile manufacturer’s installation instructions and project plans. For showers, balconies, exterior walls, or other moisture-sensitive areas, use an approved waterproofing and tile system. Treat the result as an ordering estimate and have the final layout checked before cutting or installing.