Tile Calculator Formula
Understand the math behind the tile calculator. Each variable explained with a worked example.
Formulas Used
Floor Area
total_area = floor_areaTiles (no waste)
tiles_no_waste = ceil(floor_area / tile_area_sqft)Tiles Needed
tiles_with_waste = ceil(floor_area / tile_area_sqft * (1 + waste_percent / 100))Boxes (approx, 10 tiles/box)
boxes = ceil(floor_area / tile_area_sqft * (1 + waste_percent / 100) / 10)Variables
| Variable | Description | Default |
|---|---|---|
area_length | Area Length(feet) | 12 |
area_width | Area Width(feet) | 10 |
tile_length | Tile Length(inches) | 12 |
tile_width | Tile Width(inches) | 12 |
waste_percent | Waste Factor(%) | 10 |
floor_area | Derived value= area_length * area_width | calculated |
tile_area_sqft | Derived value= (tile_length * tile_width) / 144 | calculated |
How It Works
How to Calculate Tiles Needed
Formula
Tiles = Floor Area / Tile Area × (1 + Waste %)
Convert tile dimensions from inches to feet (divide by 12) to get tile area in sq ft, then divide the total floor area by the tile area. Add 10% waste for straight layouts and 15% for diagonal layouts.
Worked Example
A 12 ft by 10 ft bathroom floor with 12×12 inch tiles and 10% waste.
- 01Floor area = 12 × 10 = 120 sq ft
- 02Tile area = 12 × 12 / 144 = 1.00 sq ft per tile
- 03Tiles needed = 120 / 1.00 = 120 tiles
- 04With 10% waste = 120 × 1.10 = 132 tiles
Frequently Asked Questions
How much tile waste should I plan for?
10% for straight/brick-pattern layouts, 15% for diagonal layouts, and 20% for complex patterns or rooms with many cuts. Always keep a few spare tiles for future repairs.
How do I calculate tiles for a wall?
Measure the wall height and width to get square footage. Then divide by the tile area and add waste, the same as for floors.
Do I need to account for grout lines?
For most residential tile sizes (12" and larger), grout lines are small enough that you do not need to adjust the count. For mosaic tiles or wide grout joints, the grout space can reduce the number of tiles needed slightly.
Learn More
Guide
How to Calculate Flooring Area and Material Quantities
Learn how to measure rooms and calculate flooring material needed for tile, hardwood, carpet, and laminate. Covers irregular rooms, waste factors, and cost estimation.
Ready to run the numbers?
Open Tile Calculator