Tile Calculator
Free tile calculator for floors, walls and backsplashes. Estimate how many tiles and boxes you need, including grout gap and waste.
Last updated: October 2026 · Multi-area, openings, layout waste, and packaging options (not a layout, thinset, or waterproofing design service)
Best for rectangular floor or wall areas. Add up to three areas for L-shapes or multiple rooms, or enter total area directly. Subtract doors and windows if needed. Use the grout gap from your product or installer. This tool estimates tile count and boxes — not thinset bags, grout volume, or waterproofing membranes.
Subtract doors and windows from the total area. Defaults: 3×7 ft doors, 3×4 ft windows. Or enter a custom total opening area to override.
Quick Answer: How Many Tiles Do I Need?
To find how many tiles you need, divide the net room area by the effective tile module (tile size plus grout gap), add waste, and round up to whole tiles.
Tiles ≈ ceil( room area ÷ ((tile length + grout) × (tile width + grout)) × (1 + waste%) ).
- Use consistent units for room and tile (this tool converts for you)
- Default grout gap: 1/8" (confirm with product or installer)
- Waste: 10% straight lay, 15–20% diagonal
- Always round up to whole tiles (and whole boxes when tiles per box is set)
Example: 10 × 12 ft with 12×12" tiles, 1/8" grout, 10% waste → about 130 tiles. Use the calculator above for your exact size and layout.
How to Use This Tile Calculator
- Choose Length × Width (add up to three areas for L-shapes or multiple rooms) or Total Area if you already know the square footage
- Optionally subtract doors and windows in the Openings section (or enter a custom total opening area)
- Enter the size of one tile and the grout gap (default 1/8" — use manufacturer guidance when known)
- Choose layout (Straight, Brick/offset, Diagonal, Herringbone, or Custom) — waste auto-fills and stays editable
- Optionally enter tiles per box and price for cost estimate
- Click Calculate Tiles to see total tiles, boxes and cost
How Many Tiles Do I Need? (Examples)
Quick reference using 12×12" tiles, 1/8" grout, and 10% waste. Re-calculate with your tile size, gap, and layout.
| Room Size | Room Area | Tiles Needed |
|---|---|---|
| 5 × 8 ft (bath) | 40 ft² | ~44 tiles |
| 10 × 12 ft | 120 ft² | ~130 tiles |
| 12 × 15 ft | 180 ft² | ~194 tiles |
| 15 × 20 ft | 300 ft² | ~324 tiles |
Figures match this calculator’s formula (straight layout, no openings). Re-run with your tile size, gap, and layout.
Worked example (10 × 12 ft floor, 12×12" tile, 1/8" grout, 10% waste)
- Gross area = 10 × 12 = 120 ft² (no openings subtracted).
- Effective tile module = (12 + 0.125) × (12 + 0.125) = 12.125" × 12.125" ≈ 1.021 ft² per tile.
- Tiles before waste = 120 ÷ 1.021 ≈ 117.5.
- With 10% waste = 117.5 × 1.10 ≈ 129.3 → ceil → 130 tiles to buy (about 12 waste tiles).
- Boxes — if 10 tiles/box: ceil(130 ÷ 10) = 13 boxes. If the carton lists 15 ft²/box: ceil(132 ÷ 15) = 9 boxes.
Same room with one 3 × 7 ft door (21 ft² opening): net area = 99 ft² → about 107 tiles after 10% waste (use Openings in the calculator for doors/windows).
Same room, 12×24" tile (1/8" grout, 10% waste)
Module ≈ 12.125" × 24.125" ≈ 2.03 ft² → about 65 tiles after waste — fewer pieces than 12×12, but each tile is larger and heavier.
Backsplash example (8 × 2 ft, 12×12" tile, 1/8" grout, 10% waste)
Area = 16 ft² → about 18 tiles after waste. For subway or mosaic sheets, enter the sheet size (or box coverage) instead of a single chip.
Recommended Waste Factor
| Layout | Waste % |
|---|---|
| Straight lay (simple room) | 5 – 10% |
| Straight lay with many cuts | 10 – 12% |
| Diagonal pattern | 15 – 20% |
| Herringbone / complex pattern | 15 – 25% |
Why diagonal and patterned layouts need more waste
Straight lays mostly cut at walls and obstacles. Diagonal, herringbone, and chevron patterns create more angled offcuts and short starter pieces, so installers typically plan 15–25% waste instead of 10%. Choose 15% or 20% in the waste dropdown when your layout is not a simple grid.
Common Tile Sizes
| Tile Size | Common Use |
|---|---|
| 12" × 12" | Floors, bathrooms |
| 12" × 24" | Modern floors & walls |
| 6" × 6" / 4" × 4" | Backsplash, showers |
| 3" × 6" subway | Kitchen backsplash |
| 18" × 18" / 24" × 24" | Large format floors |
Tiles per 100 sq ft (quick reference)
Approximate piece counts for 100 sq ft of coverage using a 1/8" grout joint. “Before waste” is the pure module math; “With 10% waste” is a typical straight-lay order quantity (always round up to whole tiles/boxes).
| Tile size | Before waste | With 10% waste |
|---|---|---|
| 12" × 12" | ~98 | ~108 |
| 12" × 24" | ~50 | ~55 |
| 6" × 6" | ~384 | ~423 |
| 3" × 6" subway | ~753 | ~829 |
| 18" × 18" | ~44 | ~49 |
| 24" × 24" | ~25 | ~28 |
Scale linearly for other areas (e.g. 150 sq ft ≈ 1.5× these counts). Diagonal or herringbone layouts need a higher waste % — use the calculator with your layout for an exact estimate.
How We Calculate Tile Quantity
This calculator estimates tile count from your area, tile size, grout joint, and waste. Steps:
- Gross area — sum of one or more rectangles (Length × Width), or the total area you enter in Total Area mode.
- Net area — subtract openings (doors, windows, or a custom opening total) when those surfaces will not be tiled.
- Unit conversion — room and tile dimensions are converted to the same units before dividing.
- Effective tile module — (Tile length + Grout gap) × (Tile width + Grout gap). This is the repeating coverage pitch, not the physical face area of the tile alone.
- Tiles before waste — Net area ÷ Effective tile module.
- Tiles to buy — apply waste % (from layout or your custom value), then round up to whole tiles.
- Boxes — if you enter tiles per box: ceil(tiles ÷ tiles per box). If you enter coverage per box: ceil(coverage with waste ÷ coverage per box).
Formulas
Effective tile module = (Tile length + Grout gap) × (Tile width + Grout gap)
Tiles before waste = Net area ÷ Effective tile module
Tiles to buy = ceil( Tiles before waste × (1 + Waste%) )
Boxes = ceil( Tiles to buy ÷ Tiles per box ) or ceil( Coverage with waste ÷ Coverage per box )
Tile size, box coverage, and installation rules vary by manufacturer. Always verify packaging and install instructions before ordering. This is a planning estimate — actual cuts and layout can change the final count.
Floor, Wall & Backsplash Tile Guide
Use the sections below for floors, walls, backsplashes, and wet areas. Enter dimensions in the calculator for a count matched to your tile size and layout.
Floors
Measure the full floor area. For L-shaped rooms, use + Add another area to enter each rectangle, or switch to Total Area mode. Need an irregular room area first? Use the square footage calculator. Large-format tiles reduce how many pieces you need, but they do not automatically mean lower waste. Waste still depends on room shape, layout, cuts, and breakage risk — lippage and flatness still matter. Follow the manufacturer’s guidance when available.
Walls & Backsplashes
Measure only the area that will be tiled. Use the Openings section to subtract windows, doors, or cabinets if they are not tiled. Backsplashes are usually measured as height × length of the wall section. After tile is in, estimate wall paint with the paint calculator.
Bathroom & shower tile
Treat each surface separately, then combine in the calculator:
- Bathroom floor — length × width. If the shower floor uses a different tile, measure that base on its own.
- Shower walls — measure each wall (width × height) and add them with + Add another area (up to three areas), or sum the wall area and use Total Area mode.
- Openings — subtract doors, windows, or large niches in the Openings section when those faces will not be tiled.
- Waste — floors often use ~10% on a straight layout; shower walls with more cuts often need 12–15% (or higher for mosaics and patterned lays).
This tool estimates tile quantity and boxes only. It does not design waterproofing membranes, shower pans, slopes, or niche framing — follow product systems and local code for wet areas. For sheet counts on dry areas of the same remodel, see the drywall calculator.
Grout gap (joint width)
Grout joint width varies by tile and installation. Common joints include 1/16", 1/8", and 3/16" — use the width recommended by the manufacturer or installer. This calculator defaults to 1/8" as a planning starting point. Including the gap in each tile dimension gives a more accurate tile count, especially with smaller tiles. This is not the same as estimating bags of grout powder.
What this calculator does not include
- Thinset / mortar coverage — follow the thinset label for bag yield
- Grout volume (lbs/bags) — depends on joint width, depth, and tile size; use manufacturer charts
- Waterproofing membranes, Schluter-type systems, or heated-floor assemblies
- Plank flooring (LVP/laminate/hardwood) — use the flooring calculator for box counts without a grout gap
How Many Boxes of Tile Do I Need?
Stores sell tile by the box, so convert your tile count (or coverage) before you order. This calculator supports both packaging styles under Packaging:
- Tiles per box known — Boxes = ceil( tiles to buy ÷ tiles per box ). Example: 130 tiles ÷ 10 per box → 13 boxes.
- Coverage per box known — Boxes = ceil( coverage with waste ÷ coverage per box ). Example: 132 ft² needed ÷ 15 ft² per box → 9 boxes.
Always round up to whole boxes. Coverage and tiles-per-box vary by product — read the carton label.
Tips for Ordering Tile
- Buy extra from the same dye lot — keep a few pieces for future repairs; shade can vary between batches.
- Confirm packaging on the carton — tiles per box and coverage differ by product.
- Acclimate tiles — let them sit in the room before installation.
Important: Planning estimate only — not a layout, substrate, thinset, or waterproofing design. Confirm cuts and product instructions with your installer.
Frequently Asked Questions
Related measurements
Need an irregular room area first? Use the square footage calculator. Installing LVP, laminate, or hardwood instead of tile? Use the flooring calculator. After tile is in, estimate wall paint with the paint calculator. Browse all construction calculators.