Tile Calculator
Estimate tile quantities and full boxes with explicit waste and metric or imperial units.
This tool runs entirely in your browser. Your data is never uploaded, never stored, and never leaves your device.
Tile Calculator estimates full boxes from net surface area and your chosen allowance, using actual rectangular tile dimensions or manufacturer-stated box coverage.
How to use it
- 1Measure a rectangle or enter the total gross area and deduct untiled sections.
- 2Choose actual tile size plus tiles per box, or supply manufacturer box coverage, then enter your allowance.
- 3Calculate full boxes, review what the estimate excludes and optionally download the JSON report.
Example
- Input
- 5 × 4 m; 2 m² exclusions; 600 × 600 mm actual tiles; 4 tiles per box; 10% allowance.
- Output
- 55 whole tiles required; 14 boxes = 56 tiles and 20.16 m² calculated coverage.
This is area-based purchasing, not a cutting layout; grout gaps are not modelled.
What happens to your data
Tile estimates run locally. Measurements are not uploaded or stored; the optional JSON report includes your active measurements and product assumptions.
Last updated October 2026
Tile purchasing starts with the area that will actually be tiled, not just the outside dimensions of a room. Measure a rectangular floor or wall, or enter a combined measured area, then deduct openings or genuinely untiled sections. This calculator adds your chosen allowance and rounds up full boxes, making the difference between net area, allowance and purchased coverage visible.
There are two ways to describe the product. Actual rectangular tile dimensions plus tiles per box provide an area-based tile count and a full-box count. If the product label already states box coverage, enter that coverage instead: the result gives boxes without inventing individual tile counts. This distinction is useful for products whose nominal trade size is different from their actual dimensions or whose packaged coverage should be used directly.
How it works
Net surface equals gross area minus excluded area. The allowance is applied to that net area before any quantity is rounded. In tile-size mode, tile area is actual length multiplied by actual width, converted from millimetres or inches. Divide the allowance-adjusted area by tile area and round up whole tiles. Divide that tile count by tiles in one box and round up whole boxes. The report shows required whole tiles and purchased tiles separately.
In box-coverage mode, divide the allowance-adjusted area by the manufacturer's stated area per box, then round up full boxes. No tile count is reported because the box coverage alone cannot establish it. Both modes show total purchased coverage and the surplus beyond your selected allowance. This is a single-product calculation: repeat it for different floor tiles, wall tiles or decorative products. Border, skirting and trim lengths are not inferred from surface area.
The calculation is not a layout planner. Tile-size mode does not model grout gaps, staggered courses, diagonal patterns, reusable offcuts, cut positions or individual irregular boundaries. A rectangular tile's area does not prove that every purchased tile can be installed without extra cuts. Your allowance is configurable from zero to 100%; it is not an installer recommendation. Discuss an appropriate allowance and the final order with the supplier or installer. Adhesive, grout, waterproofing and substrate suitability are outside this tool.
Metric mode measures surfaces in metres or m² and tile dimensions in millimetres. US customary mode uses feet or ft² for surfaces and inches for tiles. Defined conversion factors and entered decimal fractions are used exactly for whole-tile and whole-box decisions. Inputs allow six decimal places; surfaces are capped at 1,000,000 m² equivalent. Tiles per box must be a whole number from 1 to 10,000; results above 1,000,000 boxes or 1,000,000,000 tiles are refused.
Changing units clears surface and tile measurements instead of silently reinterpreting them. Any edit clears the earlier estimate and download. The JSON export records only the active product basis, measurements, allowance, quantities, exact allowance-area fraction and assumptions. It is calculated locally, but a downloaded report contains your project measurements. Displayed decimal areas are approximate; integer purchasing decisions do not use those rounded displays.
Worked example: Round a rectangular tile estimate up to whole boxes
- Input
- Surface 5 m × 4 m; untiled area 2 m²; actual tiles 600 × 600 mm; 4 tiles per box; 10% allowance.
- Result
- 18 m² net; 19.8 m² with allowance; 55 whole tiles required; 14 boxes = 56 tiles; 20.16 m² calculated purchased coverage.
The 10% allowance is an example choice. No grout gaps or cutting layout are modelled.
Common use cases
- Estimating boxes for a rectangular floor while excluding an untiled section
- Deducting a measured window area from a tiled wall
- Using actual tile dimensions instead of a rounded size in the product name
- Purchasing from manufacturer-stated box coverage without guessing the number of tiles inside
Frequently asked questions
Should I use actual tile dimensions or the advertised size?＋
Use actual rectangular dimensions from the product information. A nominal 600 mm tile may have a different actual dimension. If the manufacturer provides box coverage, the dedicated box-coverage mode lets you use that figure directly rather than recomputing it from a nominal size.
Are grout joints included?＋
No. Tile-size mode uses tile area alone, and the calculator does not create a course or cutting plan. Joint width, pattern alignment and cut reuse can change the installed quantities. Manufacturer box coverage may be a better purchasing basis for the product, but still does not validate your layout.
Does the calculator automatically recommend 10% extra?＋
No. The allowance starts at zero and is your choice. The worked example uses 10% to demonstrate the arithmetic. Different cuts, patterns, breakage risks or future spares can require a different amount; confirm it with the supplier or installer.
Why is the tile count unknown in box-coverage mode?＋
Area per box alone does not tell us the number, shape or mixture of tiles inside it. The calculator can round up boxes accurately for that stated coverage without inventing an individual count. Switch to tile-size mode only when actual dimensions and tiles per box are known.
Can I calculate an irregular room or several surfaces?＋
Measure sections separately, add their gross areas and use measured-area mode. Deduct only sections that really will not be tiled. The result remains an area-based estimate; it does not place tiles around an island, doorway or other boundary.
Does the estimate include adhesive, grout or installation checks?＋
No. Those depend on separate product specifications and site conditions. This tool does not assess substrate strength, waterproofing, movement joints or installation safety. Its job is to show an explicit area-to-box purchasing calculation.
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