Tile Calculator
Tile count, boxes, and grout lines drawn to scale on your floor or wall.
Your estimate
You'll need 43 tiles — 6 boxes, about $228.
10 columns × 4 rows · 80 sq ft of surface · 2.047 sq ft per tile with grout
Floor or wall size
Tile details
3/16 in = 0.1875
Subtract fixtures & cutouts
No openings yet. Add each door or window and its area comes out of the total.
Waste & cost
10% is standard
Your tile layout drawn to scale including grout joints, so you can see where the edge cuts fall.
The breakdown
- Tiles needed
- 43
- Boxes to buy
- 6
- Surface area
- 80 sq ft
- Areas subtracted
- −0 sq ft
- Net area to tile
- 80 sq ft
- Waste overage (10%)
- 8 sq ft
- Tile + grout footprint
- 2.047 sq ft
- Full columns × rows
- 10 × 4
- Tiles bought
- 48
- Estimated cost
- $228
Where to buy
Hand-picked search links for the materials on your list. As an Amazon Associate, ProjectMath earns from qualifying purchases.
Prices and availability are set by the retailer and change often. Always confirm the exact product size matches what this calculator assumed.
How this is calculated
Tile counts by grid, and the grout joint quietly changes the answer: each tile effectively occupies its own size plus one joint width in each direction.
- effective tile size = tile size + grout joint
- columns = ceil(room width ÷ effective tile width)
- rows = ceil(room length ÷ effective tile length)
- tiles = columns × rows, then × (1 + waste)
- boxes = ceil(tiles ÷ tiles per box)
Use 10% waste for a straight lay, 15% for a diagonal or herringbone pattern where every perimeter cut is a triangle.
- 1Measure the surfaceMeasure the width and height (or length) of the area in feet, inches, or meters and enter them in the calculator.
- 2Subtract openingsAdd each door, window, or fixture by size and count so their area is removed from the total.
- 3Enter tile size and grout widthTile plus grout joint is the real repeating unit. Enter both so the count reflects your actual layout.
- 4Add a waste overageKeep the default 10% waste allowance for cuts and mistakes, or adjust it for complex layouts and diagonal patterns.
- 5Read the shopping listThe calculator rounds up to whole units to buy and multiplies by your price per unit for an estimated total. Copy or print the plan and take it to the store.
Common questions
How many tiles do I need?
Divide the surface area by the area of one tile including its grout joint, then add waste and round up to full boxes.
How much extra tile should I buy?
10% for a straight lay, 15% for diagonal or herringbone, and always keep a few spare tiles for future repairs.
Does grout width change the tile count?
Slightly. A 1/4 inch joint on a 12 inch tile adds about 2% to each tile's footprint, which matters on large jobs.
How do I handle cut tiles at the edges?
Cut tiles are already covered by the waste overage. Try to keep edge cuts wider than half a tile by shifting your starting line.