Tile Calculator: How Many Tiles Do I Need?

Enter the area and tile size. You’ll see how many tiles and boxes to buy with waste included, how much thinset you need, and what professional installation costs.

Last reviewed: October 2026

ft
ft
%
Diagonal or herringbone: 15–20%
sq ft
Printed on the box
$per sq ft
sq ft
Check the bag for your trowel size
Your estimate

Enter your numbers. Results and charts update as you type.

How the tile calculator works

Area to buy = length × width × (1 + waste %)
Tiles = area to buy ÷ area of one tile
Boxes = area to buy ÷ coverage per box

Worked example: an 8 × 5 ft bathroom floor

The floor is 40 sq ft. Adding 10% waste gives 44 sq ft. A 12 × 24 tile covers 2 sq ft, so you need 22 tiles, or 3 boxes at 15 sq ft per box. At $3.50 per sq ft the tile costs about $158, and one 50-lb bag of thinset is enough.

Tiles per square foot

Tile sizeTiles per sq ftTiles per 100 sq ft (no waste)
3 × 6 in (subway)8800
12 × 12 in1100
6 × 24 in1100
12 × 24 in0.550
18 × 18 in0.4445
24 × 24 in0.2525

These figures ignore grout joints, which add slightly to each tile’s coverage, so they lean toward the safe side.

Tile installation cost

Installed porcelain or ceramic tile typically runs $6–$18 per sq ft, depending on tile size, pattern and how much floor prep is needed. Small mosaics and herringbone patterns sit at the top of that range.

Frequently asked questions

How much extra tile should I buy?

10% for straight layouts, 15% for diagonal or herringbone, and keep a few spares after the job for future repairs.

How much thinset do I need?

A 50-lb bag covers roughly 40–95 sq ft depending on trowel size. Large tiles need a bigger notch, so coverage drops. Check the bag.

Why do lot numbers matter?

Tiles from different production runs can differ slightly in shade. Buy everything from the same lot.

Sources: 2026 flooring cost guides from Angi, HomeGuide and Homewyse; manufacturer thinset coverage tables.

Written and reviewed by Dr. Deepak N. Paithankar, PhD in Civil Engineering. How we build our calculators.