Estimate tiles, boxes, and project costs instantly
1. Room Dimensions
2. Tile Details
3. Purchase Details
5% (Simple rectangular rooms)
10% (Standard recommendation)
15% (Diagonal layout or many corners)
20% (Complex patterns)
Total Room Area:0 sq ft
Area of One Tile:0 sq ft
Tiles Needed (Net):0 pcs
Waste Added:0 pcs (0%)
Total Tiles Required:0 pcs
Total Boxes to Buy:0 boxes
Estimated Total Cost:$0.00
function calculateTileNeeds() {
// 1. Get DOM elements
var roomLenInput = document.getElementById("roomLength");
var roomWidInput = document.getElementById("roomWidth");
var tileLenInput = document.getElementById("tileLength");
var tileWidInput = document.getElementById("tileWidth");
var tilesBoxInput = document.getElementById("tilesPerBox");
var priceBoxInput = document.getElementById("pricePerBox");
var wasteInput = document.getElementById("wasteFactor");
var resultsDiv = document.getElementById("resultsArea");
// 2. Parse values
var rLen = parseFloat(roomLenInput.value);
var rWid = parseFloat(roomWidInput.value);
var tLen = parseFloat(tileLenInput.value);
var tWid = parseFloat(tileWidInput.value);
var tPerBox = parseFloat(tilesBoxInput.value);
var price = parseFloat(priceBoxInput.value);
var wastePct = parseFloat(wasteInput.value);
// 3. Validation
if (isNaN(rLen) || isNaN(rWid) || isNaN(tLen) || isNaN(tWid)) {
alert("Please enter valid dimensions for the room and tiles.");
return;
}
// 4. Calculations
// Room Area in Sq Ft
var roomArea = rLen * rWid;
// Tile Area in Sq Ft (Inputs are in inches)
var tileAreaSqFt = (tLen * tWid) / 144;
// Raw tiles needed (mathematical)
var rawTiles = roomArea / tileAreaSqFt;
// Calculate Waste
var tilesWithWaste = rawTiles * (1 + (wastePct / 100));
// Ceiling to nearest whole tile for purchase
var totalTilesNeeded = Math.ceil(tilesWithWaste);
var netTiles = Math.ceil(rawTiles);
var wasteTilesCount = totalTilesNeeded – netTiles;
// Box calculations
var totalBoxes = 0;
var totalCost = 0;
if (!isNaN(tPerBox) && tPerBox > 0) {
totalBoxes = Math.ceil(totalTilesNeeded / tPerBox);
if (!isNaN(price)) {
totalCost = totalBoxes * price;
}
}
// 5. Update DOM
document.getElementById("resRoomArea").innerText = roomArea.toFixed(2);
document.getElementById("resTileArea").innerText = tileAreaSqFt.toFixed(3);
document.getElementById("resNetTiles").innerText = netTiles;
document.getElementById("resWastePct").innerText = wastePct;
document.getElementById("resWasteTiles").innerText = wasteTilesCount;
document.getElementById("resTotalTiles").innerText = totalTilesNeeded;
if (totalBoxes > 0) {
document.getElementById("resTotalBoxes").innerText = totalBoxes;
} else {
document.getElementById("resTotalBoxes").innerText = "—";
}
if (totalCost > 0) {
document.getElementById("resTotalCost").innerText = totalCost.toFixed(2).replace(/\B(?=(\d{3})+(?!\d))/g, ",");
} else {
document.getElementById("resTotalCost").innerText = "0.00";
}
// Show results
resultsDiv.style.display = "block";
}
How to Calculate Tiles for Your Flooring Project
Whether you are renovating a bathroom, tiling a kitchen backsplash, or laying down a new patio, accurately calculating the number of tiles you need is the first critical step to a successful project. Buying too few tiles leads to project delays and mismatched dye lots, while buying too many is a waste of budget. This calculator helps you determine exactly how many boxes to purchase based on room size, tile dimensions, and waste factors.
1. Measuring Your Space
To use the tile calculator effectively, you need precise measurements of your room. Measure the maximum length and maximum width of the floor in feet. If your room is not a perfect rectangle (L-shaped, for example), divide the room into smaller rectangular sections, calculate the area for each, and add them together before entering the total dimensions into the calculator.
Formula:Area = Length (ft) × Width (ft)
2. Why the Waste Factor Matters
One of the most common mistakes DIYers make is failing to account for "waste." You cannot simply divide the room area by the tile area. You must add a percentage for cuts, breakage, and future repairs.
10% Waste: The industry standard for simple, square rooms with basic grid patterns.
15% Waste: Recommended for rooms with many corners, pillars, or obstacles that require intricate cuts.
20% Waste: Necessary if you are laying tiles in a diagonal (diamond) pattern. Diagonal layouts generate significantly more scrap material at the perimeter of the room.
Pro Tip: Always keep at least one full box of tiles leftover after the installation is complete. If a tile cracks a year later, you will have a perfect match for replacement.
3. Understanding Tile Sizes and Coverage
Tiles are sold in various standard sizes, usually measured in inches. Common sizes include:
Subway Tile: 3″ x 6″ (0.125 sq ft per tile)
Standard Square: 12″ x 12″ (1 sq ft per tile)
Large Format: 12″ x 24″ (2 sq ft per tile)
Plank Tile: 6″ x 36″ (1.5 sq ft per tile)
Our calculator automatically converts your tile dimensions (inches) into square footage to ensure an accurate calculation against your room dimensions (feet).
4. Calculating Boxes and Cost
Tiles are rarely sold individually; they are packaged in boxes (cartons). To get the final purchase list, you divide the total required tiles by the number of tiles per box and round up to the next whole box. Even if you only need 1 extra tile, you must purchase a full box.
Budgeting: Don't forget to factor in the cost of grout, thin-set mortar, and underlayment, which typically add $1.00 – $3.00 per square foot to your total project cost.