Tile Calculator
Calculate exactly how many tiles you need for any floor or wall. Enter room size, tile dimensions, grout spacing, and waste allowance for instant results.
How to Calculate How Many Tiles You Need
Calculating tile quantities involves several steps. Here's the complete formula this calculator uses:
- Calculate total area: Multiply room length × room width to get the square footage (or square meters).
- Calculate tile area: Multiply tile length × tile width (including grout spacing) to get the area per tile.
- Calculate number of tiles: Divide total area by tile area.
- Add waste allowance: Multiply the tile count by (1 + waste percentage).
- Round up: Always round up to the nearest whole tile.
- Calculate boxes: Divide by tiles per box and round up.
Example: A 12ft × 15ft room has an area of 180 sq ft. Using 12×12 inch tiles (1 sq ft each) with ⅛ inch grout, you'd need about 180 tiles. With 15% waste, that's 207 tiles. At 10 tiles per box, you'd need 21 boxes.
Why Use This Tile Calculator?
- Avoid overbuying or underbuying: Get the exact number of tiles needed for your project.
- Account for grout: Grout lines affect the effective tile size — this calculator includes them.
- Pattern-specific waste: Different installation patterns require different waste allowances.
- Save money: Buy only what you need, plus a few extras for future repairs.
Important Tips for Buying Tiles
- Buy from the same dye lot: Tile colors vary between batches — always check the lot number.
- Buy extra tiles: Keep a few tiles in the garage for future repairs (water damage, cracks).
- Check the box coverage: Most tile boxes state the coverage in square feet — use that to double-check your calculations.
- Order samples first: See the tile in your lighting before buying in bulk.
- Consider tile thickness: Floor tiles (thicker) vs wall tiles (thinner) have different installation requirements.
How Accurate Is This Calculator?
This calculator uses industry-standard formulas recommended by the Tile Council of North America (TCNA). Results are accurate to within 1-2 tiles for most rooms. For rooms with complex shapes (alcoves, bay windows, sloped ceilings), we recommend consulting a professional tile installer.
Frequently Asked Questions
Measure the length and width of the area to get the total square footage. Then divide by the area of each tile (including grout spacing). Add 10-15% for waste and cuts. This calculator does all the math for you instantly.
Common tile sizes include 12×12 inches, 12×24 inches, 18×18 inches, 24×24 inches for floors, and 4×4, 6×6, 8×10 inches for walls. Subway tile (3×6 inches) is also very popular for backsplashes and bathrooms.
Buy 10-15% extra for rectangular rooms, 15-20% for diagonal patterns, and 20-25% for complex layouts with many cuts. Also buy 1-2 extra boxes for future repairs.
Yes, larger grout lines mean fewer tiles are needed because each tile covers slightly more area. A ⅛ inch grout line adds about 1-2% to the effective tile size, which can reduce the total number of tiles by a small amount.
Tile boxes typically cover 10-15 square feet. Common box sizes: 12×12 tiles usually have 10-12 per box (10 sq ft), 12×24 tiles have 5-8 per box (10 sq ft), and mosaic tiles have more pieces per box. Always check the box for the exact coverage.
Floor tiles are thicker, more durable, and have higher slip resistance. Wall tiles are thinner, lighter, and often have a decorative finish. For floors, use tiles with a PEI rating of 3 or higher for residential use.