Tile Calculator — How Many Tiles Do I Need?

How to Calculate Tile for Any Project

Getting the right amount of tile is crucial — running short mid-project means a trip back to the store and risking a different dye lot. Buying too much wastes money. This guide covers the exact math for floors, walls, backsplashes, and showers.

The Basic Formula

Area (sq ft) = Length × Width

Then: Number of Tiles = Area ÷ Tile Size (in sq ft) + waste percentage

For grout lines, add the grout width to each tile dimension before calculating coverage. A 12×12 tile with 1/8" grout lines effectively covers 12.125 × 12.125 inches — which adds up over large areas.

Waste Percentages by Layout

Layout Pattern	Waste %	Why
Straight / Grid	10%	Simplest cuts, least waste
Brick / Running Bond	12%	Offset cuts at walls
Diagonal (45°)	15%	Every edge requires an angle cut
Herringbone	15–20%	Complex cuts at all edges
Chevron	18–20%	Mitered cuts, high precision needed

Tile Sizes: What Works Where

Size	Best For	Price Range/sq ft
1"×1" – 2"×2" Mosaic	Shower floors, accents, backsplashes	$5–$25
3"×6" Subway	Backsplashes, shower walls, classic look	$2–$10
12"×12"	Floors, walls — the versatile standard	$2–$12
12"×24"	Modern floors, fewer grout lines, spacious feel	$3–$15
6"×24" – 8"×48" Planks	Wood-look floors, trending in 2026	$3–$12
24"×24" Large Format	Open floor plans, commercial spaces	$5–$20

Materials Checklist Beyond Tile

Don't forget these essential supplies when estimating your project budget:

• Thinset morite: 1 bag (50 lb) covers ~60–80 sq ft. Budget $15–$30/bag.
• Grout: 1 bag (25 lb) covers ~75–200 sq ft depending on tile size and joint width. $12–$25/bag.
• Backer board: Required over plywood subfloors. $10–$15 per 3×5 sheet. You need one sheet per 15 sq ft.
• Tile spacers: $3–$8 per bag. Get the size matching your grout line width.
• Sealer: For natural stone and unglazed porcelain. $15–$30 per quart.
• Transition strips: Where tile meets other flooring. $5–$20 each.

Pro Tips for Accurate Tile Estimation

• Measure each wall or section separately — especially for backsplashes with windows, outlets, and varied heights.
• Subtract areas you won't tile: vanity footprint, toilet flange, window openings. But keep the waste factor — it already accounts for this.
• Always round up to full boxes. You can't buy partial boxes, and leftover tiles are cheap insurance for future repairs.
• Check the dye lot. Tiles from different manufacturing batches may have slight color differences. Buy everything at once.
• Large-format tiles cost more to install because they require a flat substrate, more thinset, and careful handling.

DIY vs. Professional Installation

	DIY	Professional
Cost (per sq ft)	$2–$8 (materials only)	$7–$25 (materials + labor)
Time (100 sq ft bathroom)	2–4 days	1–2 days
Tools Needed	Wet saw, trowels, spacers, level	Included
Best For	Simple floors, subway backsplashes	Complex patterns, large format, showers
Risk	Lippage, uneven grout, waterproofing errors	Low (if contractor is qualified)