Tile Quantity Calculator
This Tile Quantity Calculator estimates the number of tiles, boxes, and the material cost required for a rectangular floor area. Enter measurements in metres and specify grout width in millimetres; the calculator accounts for grout spacing and a customizable waste allowance to cover cuts and breakage.
Results are conservative estimates for planning and purchasing. For complex room shapes, patterns, or steps, use this as a baseline and measure additional areas separately. For unit guidance and measurement standards, consult recommended references from national standards bodies and building science resources listed below.
Inputs
Results
Floor area (m²)
12
Tile coverage area including grout (m²)
0.0918
Tiles required (no waste)
130.7061
Tiles required (including waste)
—
Boxes needed
—
Estimated material cost
—
| Output | Value | Unit |
|---|---|---|
| Floor area (m²) | 12 | m² |
| Tile coverage area including grout (m²) | 0.0918 | m² |
| Tiles required (no waste) | 130.7061 | — |
| Tiles required (including waste) | — | — |
| Boxes needed | — | — |
| Estimated material cost | — | — |
Visualization
Methodology
We compute the floor area as length × width. Each tile's effective coverage equals (tile length + grout gap) × (tile width + grout gap); grout width is converted from millimetres to metres in the calculation.
Tiles required = floor area ÷ effective tile coverage. We then apply your waste percentage and round up to whole tiles and boxes because tiles are sold in whole units. Box quantity is the rounded-up tiles divided by tiles per box, rounded up again.
Cost is calculated from boxes needed × price per box. Values are estimates; always verify with on-site measurements before final purchase.
Expert Q&A
Can I enter dimensions in imperial units (feet/inches)?
This calculator expects metric inputs (metres for lengths, millimetres for grout). If you work in imperial units, convert to metres before entering values. NIST provides reliable unit-conversion guidance for accurate conversion.
How much waste percentage should I use?
Typical waste allowances range from 8% to 15% for straight layouts. Use higher values (10%–20%) for diagonal patterns, border cuts, or irregular rooms. For large format tiles or critical installations consult your installer or manufacturer recommendations.
Why does grout width change the number of tiles?
Grout creates spacing between tiles; the repeat pitch (tile size plus grout) determines how much floor area each tile covers. A wider grout increases the area consumed by spacing and can slightly reduce the number of tiles covering a given floor area.
How accurate is the cost estimate?
Cost is a simple multiplication of boxes needed by price per box. It does not include delivery, adhesive, grout, underlayment, labor, or waste on returned/exchanged boxes. Use the material cost here as a purchasing baseline and add quotes from suppliers and installers for full project budgeting.
What about irregular rooms, alcoves, or staircases?
Divide the project into rectangles or usable geometric sections, calculate each separately, then sum the tile quantities. For irregular shapes, measure and sketch the area, or consult a professional for templating to minimize waste.
Do building codes or safety standards affect tile quantity?
Quantity calculations are independent of most building codes, but codes and standards can affect tile selection (slip resistance, load rating) and installation methods. Refer to relevant local building codes and standards for compliance; consult an architect or licensed installer when in doubt.
Sources & citations
- NIST — SI Units and Unit Conversion Guidance — https://www.nist.gov/pml/weights-and-measures/si-units
- ISO — Standards for Ceramic Tiles (overview) — https://www.iso.org/standard/60564.html
- MIT OpenCourseWare — Building Technology and Construction Resources — https://ocw.mit.edu
- OSHA — Walking-Working Surfaces (guidance relevant to floor finishes) — https://www.osha.gov/walking-working-surfaces