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Interior & Finishes

Tile Calculator

This tile calculator counts tiles and boxes for floors, walls and backsplashes; our flooring installation guide covers layout and costs. Enter the area to cover, your tile size and the grout joint width. The calculator works out how many tiles fit per square foot (including the joint), adds a waste allowance for cuts and breakage, and converts to boxes. Use roughly 10% waste for straight layouts and 15% or more for diagonal or herringbone patterns.

Results from this tile calculator are planning estimates; confirm quantities and prices with your supplier or contractor before you order.

Enter your project

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1/16–1/8 in for rectified tile; 1/4 in or more for rustic tile.

%

10% straight lay; 15% diagonal; 20% herringbone or many cuts.

$/sq ft

Results

Your results will appear here

Enter your measurements and press Calculate. Defaults show a typical example.

How to use the tile calculator

  1. Measure the area (split L-shaped rooms into rectangles and add them).
  2. Enter tile length and width in inches and your grout joint.
  3. Pick a waste allowance that matches your layout.
  4. Enter tiles per box from the carton to get the number of boxes.

Formula

Tiles = area (sq ft) × 144 ÷ ((tile length + joint) × (tile width + joint)) × (1 + waste), rounded up.

Worked example

100 sq ft of 12 × 12 in tile with 1/8 in joints: each tile covers 1.021 sq ft → 97.9 tiles, or 108 tiles with 10% waste.

Tips for using the tile calculator

  • Use 10% waste for straight layouts and 15% for diagonal, herringbone or large-format tile.
  • Keep a spare box after the job for future repairs; discontinued tile is hard to match.
  • Check box coverage on the label rather than counting tiles per box.
  • Dry-lay a row of tile before you mix thinset to check the layout; centering the pattern in the room avoids thin slivers at walls and doorways that look like mistakes.
White subway tile shower wall beside a black-and-white patterned tile accent wall

Tile Calculator FAQs

How many 12×12 tiles in 100 square feet?

About 98 with 1/8 in joints, or 108 with 10% waste.

Why buy extra tile?

Cuts at walls and fixtures, breakage and future repairs. Tile runs vary in shade between production lots, so matching later can be hard — keep a few spare tiles.

How much does tile installation cost?

See our flooring and tile guide for typical installed-cost ranges.

Estimate before you call a contractor

Run the numbers with our free calculators so you can compare bids with confidence.

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