Ordering tile is one of those jobs where guessing costs real money. Order too little and your project stalls while you hunt for the same dye lot; order too much and you’ve paid for boxes that live in the garage forever. Our free tile calculator removes the guesswork — enter your room size and tile size into the tile calculator, and it tells you exactly how many tiles to buy, plus grout and thinset, with a proper waste allowance built in.

Open the Tile Calculator →

What the Tile Calculator Tells You (Specifications)

The calculator takes four inputs and produces a complete materials list:

• Room dimensions — length and width in feet. The tool converts to square footage automatically.
• Tile size — 12×12, 18×18, 24×24 or 12×24 inches, the four most common residential formats.
• Waste allowance — 10% for simple straight layouts, 15% standard, 20% for diagonal or intricate patterns.
• Outputs: exact tile count (rounded up), 25 lb grout bags (roughly one per 40 sq ft), and 50 lb thinset bags (roughly one per 90 sq ft).

The math is simple but strict: total area x 144 ÷ tile area in square inches, multiplied by your waste factor, then rounded up. No partial tiles to buy, no shortfall at the end of the job.

How to Use It — Step by Step

1. Measure the room. Take length and width in feet at the longest points. For L-shaped rooms, measure two rectangles and add them.
2. Open the calculator and enter both measurements.
3. Choose your tile size from the dropdown — match what you plan to buy.
4. Pick a waste allowance. Straight grid layout: 10%. Standard with a few cuts: 15%. Diagonal, herringbone or lots of obstacles: 20%.
5. Hit calculate and note the tile count, grout and thinset figures. Screenshot the result for the tile shop.

Designer Tips for Buying Tile

• Buy one full extra box from the same dye lot. Future repairs need an exact match, and dye lots vary between batches.
• Large-format tiles (24×24) need a flatter floor — budget for floor leveling if your subfloor is uneven.
• Diagonal layouts look bigger but eat more tile — the 20% waste setting exists for a reason.
• Pair this with our paint calculator when refreshing a whole room, so materials and wall finishes are planned together.

FAQs

How many tiles do I need for a 12×12 room?
144 sq ft needs roughly 144 twelve-inch tiles before waste — about 166 with the standard 15% allowance. Use the calculator above for your exact tile size.

What is the waste factor for tile?
10% for simple straight layouts, 15% as a standard rule, 20% for diagonal or complex patterns. Professionals never order without one.

How much grout do I need?
Roughly one 25 lb bag of grout per 40 sq ft of tile. The calculator estimates this automatically from your room size.

Ready to plan your project? Open the free tile calculator and get your exact materials list in under a minute.