Planning a tiling project—whether it's a bathroom floor, a kitchen backsplash, or a patio—requires precise measurements to ensure you purchase the right amount of material. Buying too few tiles can lead to project delays and mismatched dye lots, while buying too many is an unnecessary expense. Our Tile Calculator helps you estimate exactly what you need.
Step 1: Determine the Room Area
The first step in any flooring project is calculating the total square footage of the area to be tiled. For a standard rectangular room, simply measure the length and width in feet and multiply them together:
Formula: Length (ft) × Width (ft) = Area (sq ft)
Example: A 10ft x 12ft room = 120 square feet.
Step 2: Calculate Tile Coverage
Next, you need to know the area covered by a single tile. Since tiles are usually sold in inches, you must convert the area to square feet to match your room measurements.
Formula: (Tile Length (in) × Tile Width (in)) ÷ 144 = Sq Ft per Tile
Example: A 12″ x 12″ tile is 1 sq ft. A 6″ x 24″ plank tile is also 1 sq ft.
Step 3: Factor in Wastage (Critical!)
One of the most common mistakes DIYers make is failing to account for wastage. You cannot simply divide the room area by the tile area. You must purchase extra tiles to account for:
Cuts: Tiles along the walls will need to be cut, rendering the off-cut often unusable.
Breakage: Tiles may crack during shipping or cutting.
Pattern Matching: Complex patterns often result in more waste.
Recommended Overage:
10%: Standard for general tiling projects.
15%: For rooms with many obstacles (toilets, islands, pillars) or diagonal layouts.
Common Tile Sizes
While tiles come in infinite varieties, standard sizes include:
Subway Tile: 3″ x 6″
Square Floor Tile: 12″ x 12″ or 16″ x 16″
Large Format: 12″ x 24″ or 24″ x 24″
Plank Tile: 6″ x 24″ or 6″ x 36″
function calculateTiles() {
// 1. Get Input Values
var rLen = parseFloat(document.getElementById('roomLength').value);
var rWid = parseFloat(document.getElementById('roomWidth').value);
var tLen = parseFloat(document.getElementById('tileLength').value);
var tWid = parseFloat(document.getElementById('tileWidth').value);
var wastePct = parseFloat(document.getElementById('wastePercent').value);
var priceSqFt = parseFloat(document.getElementById('pricePerSqFt').value);
// 2. Validate Inputs
if (isNaN(rLen) || isNaN(rWid) || isNaN(tLen) || isNaN(tWid)) {
alert("Please enter valid numbers for all room and tile dimensions.");
return;
}
if (rLen <= 0 || rWid <= 0 || tLen <= 0 || tWid 0) {
totalCost = totalCoverageSqFt * priceSqFt;
document.getElementById('cost-row').style.display = 'flex';
document.getElementById('res-total-cost').innerText = '$' + totalCost.toLocaleString(undefined, {minimumFractionDigits: 2, maximumFractionDigits: 2});
} else {
document.getElementById('cost-row').style.display = 'none';
}
// 5. Update UI
document.getElementById('res-area').innerText = roomAreaSqFt.toFixed(2) + " sq ft";
document.getElementById('res-net-tiles').innerText = Math.ceil(netTiles);
document.getElementById('res-waste-tiles').innerText = wasteTiles + " tiles (" + wastePct + "%)";
document.getElementById('res-total-tiles').innerText = totalTiles;
// Show results container
document.getElementById('tc-results').style.display = 'block';
}