Tile Calculator

About Tile Calculator

This tile calculator estimates how many tiles you need for a floor or wall project. Enter the area dimensions and tile size, set a waste percentage for cuts, and optionally calculate cost per tile, total cost, and box count. It supports common tile presets, custom dimensions, and grout gap adjustments for accurate counts.

How the Tile Count Is Calculated

Step	Formula	Example (100 sq ft room, 12x12 in tiles, 1/8 in grout)
Effective tile size	Tile dimension + Grout gap	12 + 0.125 = 12.125 inches each way
Effective tile area	Effective width x Effective height	12.125 x 12.125 = 147.02 sq in = 1.021 sq ft
Tiles needed (exact)	Room area / Effective tile area	100 / 1.021 = 97.9 tiles
Tiles needed (rounded up)	Ceiling of exact count	98 tiles
With 10% waste	Tiles x 1.10	98 x 1.10 = 107.8, rounded to 108 tiles
Boxes needed	Tiles / Tiles per box (rounded up)	108 / 12 = 9 boxes

Common Tile Sizes

Size (inches)	Area per Tile (sq ft)	Common Name	Typical Use
3 x 6	0.125	Subway tile	Kitchen backsplash, bathroom walls
4 x 4	0.111	Standard small tile	Accent walls, shower niches
6 x 6	0.25	Small square	Bathroom floors, shower walls
12 x 12	1.0	Standard square	Floors, walls, most versatile size
12 x 24	2.0	Large format rectangle	Modern floors, feature walls, makes small rooms look bigger
18 x 18	2.25	Large square	Large floor areas, open-plan rooms
24 x 24	4.0	Extra large	Commercial floors, large modern bathrooms
2 x 2 mosaic sheet	~1.0 (per sheet)	Mosaic	Shower floors, decorative accents

Waste Percentage Guide

Tile waste comes from cuts at edges, around obstacles, and breakage during installation. The right waste factor depends on the layout pattern:

Layout Pattern	Recommended Waste %	Why
Straight lay (grid)	10%	Minimal cuts; edges only
Brick / running bond (offset)	10-12%	Slightly more edge cuts from the offset
Diagonal (45 degree)	15%	Every edge piece is a triangle cut
Herringbone	15-20%	Complex angles, many small cuts
Complex pattern / mixed sizes	20%+	Multiple tile sizes, more breakage risk
Rooms with many obstacles	15%+	Pipes, toilets, cabinets all require cuts

Grout Gap Sizes

Gap Width	Typical Use	Notes
1/16 inch (1.5 mm)	Rectified (precision-cut) tiles	Very tight; requires perfectly flat substrate
1/8 inch (3 mm)	Standard wall and floor tiles	Most common residential gap
3/16 inch (5 mm)	Handmade or irregular tiles	Wider gap accommodates size variation
1/4 inch (6 mm)	Outdoor tiles, rustic styles	Allows for thermal expansion

Wider grout gaps reduce the number of tiles needed slightly because each tile's effective coverage area increases. The calculator accounts for this automatically.

Cost Estimation

Enter a price per tile and tiles per box to get a total cost estimate and box count. The calculator supports multiple currencies. Remember to budget for additional costs beyond tiles:

Item	Typical Cost Range	Notes
Tiles	$1-15 per sq ft	Ceramic cheapest, natural stone most expensive
Thinset mortar	$15-30 per 50 lb bag	One bag covers ~50-75 sq ft
Grout	$10-25 per 25 lb bag	One bag covers ~75-100 sq ft depending on tile size and gap
Backer board (wet areas)	$10-15 per 3x5 sheet	Required in showers and tub surrounds
Professional installation	$5-15 per sq ft	Varies by region and complexity

Tile Selection Tips

Consideration	Recommendation
Small bathroom	Larger tiles (12x24) reduce grout lines and make the space feel bigger
Shower floor	Small mosaic tiles (2x2 or smaller) are easier to slope toward the drain
Kitchen floor	Porcelain or ceramic 12x12 or larger; avoid polished finishes (slippery when wet)
Backsplash	Subway tile (3x6) is classic; measure the exact wall area to avoid over-ordering
Outdoor patio	Porcelain rated for outdoor use (frost-proof, slip-resistant)

For measuring your room area before tiling, the square footage calculator converts dimensions to square feet. If you also need paint for walls above the tile, the paint calculator estimates gallons and coverage. All calculations run in your browser with no data stored.