How to calculate it
Calculate the surface area and tile area using consistent units. Divide the surface area by tile area, allow for cuts, and round up to full boxes.
Worked example
An 80 sq ft surface with 12 × 12 in tiles requires 80 tiles before waste. With a 15% cutting allowance, allow for 92 tiles. Ten tiles per box means purchasing 10 boxes.
Before you order
- Diagonal patterns, niches, corners and large-format tiles can increase losses.
- Measure areas around fixtures separately; the estimate does not solve a tile-cutting pattern.
- Order matching dye lot and calibre when possible.
Frequently asked questions
Does grout spacing count?
The calculation ignores grout joints, producing a conservative area estimate. Complex joint patterns should be laid out manually.
Can I calculate wall tile?
Yes. Enter the height as one surface dimension and width as the other, then calculate separate sections as necessary.
Is waterproofing included?
No. Backer board, waterproofing membrane, adhesive, grout and labour are separate expenses.
Sources & assumptions
Geometry-based estimate. Your product specifications and supplier instructions take priority.
Calculator formulas and explanations prepared for RenovationBinder, 2026-10-15.