How to use this floor tile square footage calculator
One or more tiled floors, including L-shaped rooms represented by simple, non-overlapping rectangles.
- Add the finished room, wall, floor, or ceiling dimensions. Split irregular areas into non-overlapping rectangles.
- Choose the measurement unit, enter the tile details, and select a waste percentage that suits the layout.
- Use the coverage printed on the manufacturer's box, then calculate to see area, tile count, and the whole boxes to order.
Measure before you estimate
Measure the clear floor length and width for each rectangular area. Break an L-shaped or stepped room into rectangles that do not overlap; add alcoves as their own sections. Deduct a floor opening only if it will not receive tile. Measure tile face dimensions and consult the package for square-foot coverage.
How the calculation works
The calculator adds each rectangular section's length × width, subtracts any entered untiled opening, applies waste, and divides by the tile face area and box coverage. Counts are rounded upward, since partial tiles and partial boxes cannot be purchased as whole quantities.
Worked example
Example: an L-shaped floor
An L-shaped room can be split into an 8 ft × 10 ft rectangle and a non-overlapping 4 ft × 5 ft extension.
Working: Add 80 + 20 = 100 sq ft. At 10% extra, the planned material area is 110 sq ft. If boxes cover 15 sq ft each, the estimate is ceil(110 ÷ 15) = 8 boxes.
Common measurement mistakes
- Counting overlapping rectangles twice when splitting an irregular outline.
- Measuring around built-ins that will not be tiled.
- Forgetting to round up partial boxes after adding waste.
Choosing a tile waste percentage
For a square room with a straight lay, 10% is a common planning start. A diagonal or herringbone pattern, narrow perimeter cuts, several doorways, or an irregular outline can increase offcuts; consider 15% or more after consulting the installer.
Always check the product's actual coverage and installation instructions before buying. Cuts, breakage, grout joints, package quantities, and future repair stock can change the final quantity.
Quick answers
Frequently asked questions
How do I calculate tile for an L-shaped room?
Divide it into rectangles that do not overlap, calculate each rectangle's length times width, and add the areas. Subtract any untiled cutout separately.
How much tile waste should I add for a floor?
Ten percent is often used as a starting allowance for a simple straight pattern. Cuts, room shape, pattern, tile size, and availability of replacement stock can change the amount.
Do I round up tile boxes?
Yes. Divide the area including waste by the coverage per box, then round up to a whole box.
Continue planning