Tile Calculator — How Many Tiles Do I Need?
Estimate tiles, boxes, mortar, and grout for floors, walls, and backsplash projects. Supports any tile size with adjustable grout spacing and waste factor for diagonal or complex patterns.
Tile Calculator
Common Tile Sizes
| Size (in) | Size (cm) | Coverage | Best For |
|---|---|---|---|
| 4 × 4 | 10 × 10 | 0.111 sq ft (0.010 m²) | Backsplash, accent |
| 6 × 6 | 15 × 15 | 0.25 sq ft (0.023 m²) | Backsplash, walls |
| 12 × 12 | 30 × 30 | 1.0 sq ft (0.093 m²) | Floors (most common) |
| 12 × 24 | 30 × 60 | 2.0 sq ft (0.186 m²) | Modern floors, walls |
| 18 × 18 | 45 × 45 | 2.25 sq ft (0.209 m²) | Large rooms |
| 24 × 24 | 60 × 60 | 4.0 sq ft (0.372 m²) | Open floor plans |
How to Calculate Tiles
- Measure the area in feet (or meters): length × width = sq ft (or m²).
- Calculate effective tile size by adding grout spacing to each dimension.
- Divide area by tile area to get base tile count.
- Add waste factor (10–20% depending on pattern).
- Divide by tiles per box and round up to get boxes needed.
Imperial example: 10×10 ft floor with 12×12 in tiles, 1/8″ grout, 10% waste, 10 tiles/box. Effective tile = 12.125″ × 12.125″ = 1.021 sq ft. Tiles = 100 ÷ 1.021 = 98. With 10% waste = 108 tiles = 11 boxes.
Metric example: 3×3 m floor with 30×30 cm tiles, 3 mm grout, 10% waste. Area = 9 m². Effective tile = 0.303 m × 0.303 m = 0.0918 m². Tiles = 9 ÷ 0.0918 = 98. With 10% waste = 108 tiles.
Tile Layout Patterns & Waste
- Straight (grid): 10% waste. Easiest, fewest cuts.
- Brick / offset: 10–15% waste. Each row offset by half a tile.
- Diagonal (45°): 15% waste. Tiles set on the diagonal — more cuts at edges.
- Herringbone: 20% waste. Rectangular tiles in V pattern. Visually striking, lots of cuts.
- Versailles / French: 15–20% waste. Mix of large and small square/rectangular tiles.
Mortar and Grout Guide
| Material | Coverage | Best For |
|---|---|---|
| Thinset (1/4″ v-notch) | 50 sq ft (4.6 m²) per 50 lb bag | Tiles up to 12×12 |
| Medium-bed mortar (1/2″ trowel) | 30 sq ft (2.8 m²) per 50 lb bag | Large-format tiles > 15″ |
| Sanded grout | ~25 sq ft (2.3 m²) per 25 lb bag | Joints > 1/8″ (3 mm) |
| Unsanded grout | ~50 sq ft (4.6 m²) per 25 lb bag | Joints ≤ 1/8″ (3 mm) |
| Epoxy grout | ~30 sq ft (2.8 m²) per 9 lb kit | Wet areas, high traffic, stain-resistant |
Frequently Asked Questions
How many 12×12 tiles for 100 sq ft?
Each 12×12 tile covers 1 sq ft, so 100 tiles base. With 1/8″ grout joints, effective tile area is 1.021 sq ft → about 98 tiles. Add 10% waste = 108 tiles, or 11 boxes (10/box). For diagonal patterns add 15%.
How much extra tile should I buy for waste?
10% for straight patterns, 15% for diagonal, 20% for herringbone or complex patterns. Always buy from the same dye lot — order all your tile at once to avoid color mismatch.
What grout spacing should I use?
1/16″ (1.5 mm) for rectified tiles, 1/8″ (3 mm) for standard ceramic, 3/16″ (5 mm) for natural stone, 1/4″ (6 mm) for handmade or rustic tiles. Larger gaps need sanded grout; smaller use unsanded.
How much thinset mortar do I need?
About 1 bag (50 lb / 22.7 kg) per 50 sq ft (4.6 m²) using a 1/4″ (6 mm) v-notch trowel. Larger tiles or back-buttering increases consumption to ~40 sq ft (3.7 m²) per bag.
Related Calculators
- Drywall Calculator — for the wall surface beneath your tile
- Sand Calculator — for tile leveling base
- Paver Calculator — outdoor pavers and patio stones
- Carpet Calculator — carpeting an adjacent room instead?
- Paint Calculator — painting walls or ceiling above the tile?
- Pool Volume Calculator — tiling a pool or spa?
- Square Feet to Square Meters — convert tile area between imperial and metric
- All Construction Calculators
Tile counts include grout spacing in the effective dimension. Mortar and grout coverages are typical with the trowel sizes noted; back-buttering large tiles consumes more. Always buy 10–20% extra and from the same dye lot.
