Tile Calculator
Calculate exactly how many tiles you need for any floor or wall installation. Accounts for tile size, grout gaps, wastage, and optional cost estimation.
Area to Tile
Tile Size
Installation Options
1/8" (0.125) is standard for most tiles.
10% straight lay, 15% diagonal, 20% herringbone.
Cost Estimation
(Optional)Tile Estimate
To cover your 10 ft × 12 ft area (120 sq ft) with 12×12 inch tiles and a 1/8 inch grout gap, you will need approximately 118 tiles. Including 10% wastage, you should order 130 tiles.
How many tiles do you actually need?
Whether you’re retiling a bathroom floor, laying a kitchen backsplash, or covering an entire living room, running out of tiles mid-project is one of the most frustrating mistakes you can make. Our tile calculator takes the guesswork out — enter your room dimensions, tile size, and grout gap, and get an instant count of exactly how many tiles to order, including wastage.
The math is simple, but the details matter. A grout gap of even 1/8 inch can change your tile count by several pieces across a large room. And without accounting for waste from cuts and breakage, you’ll find yourself ordering more tiles at the last minute — often from a different batch that doesn’t quite match.
How to calculate tiles by hand
Here’s the step-by-step process for figuring out your tile count:
- Measure your area. Multiply length by width to get total square footage (or square meters).
Area = Length × Width
- Calculate effective tile size. Add the grout gap to both tile dimensions.
Effective Tile Area = (Tile Length + Gap) × (Tile Width + Gap)
- Divide area by tile size. This gives you the exact number of tiles needed.
Tiles Needed = Area ÷ Effective Tile Area
- Round up to the nearest whole number — you can’t buy half a tile.
- Add wastage. Multiply by 1 + (waste percentage / 100).
Tiles to Order = Tiles Needed × (1 + Waste%)
Example: A 10 ft × 12 ft room with 12×12 inch tiles, 1/8 inch grout gap, and 10% waste:
- Room area = 10 × 12 = 120 sq ft
- Effective tile area = (12 + 0.125) × (12 + 0.125) = 147.02 sq in = 1.021 sq ft
- Tiles needed = 120 ÷ 1.021 = 117.5 → 118 tiles
- With 10% waste = 118 × 1.10 = 129.8 → 130 tiles
Understanding grout gaps
The gap between tiles isn’t just aesthetic — it serves a structural purpose. Tiles are rarely perfectly uniform in size, and grout joints allow for slight variations during installation. Without gaps, tiles would butt against each other and create uneven edges or lippage.
Standard grout gaps for residential tile:
- 1/16 inch (1.5mm): Rectified porcelain tiles with precision edges. Minimal grout lines for a sleek look.
- 1/8 inch (3mm): The most common default for ceramic and porcelain floor tiles. Works well for most installations.
- 3/16 inch (5mm): Larger format tiles or areas with slight size variation.
- 1/4 inch (6mm): Handmade or rustic tiles, natural stone, or when you want the grout line to be a visible design element.
Wider grout gaps slightly reduce the number of tiles needed, but the difference is minimal for most rooms. The calculator accounts for this automatically.
How much waste should you plan for?
Waste comes from three sources: cuts at edges and obstacles, breakage during handling and cutting, and pattern alignment. How much you need depends on your layout:
| Layout Type | Waste % | Why |
|---|---|---|
| Straight lay, rectangular room | 10% | Minimal cuts, predictable pattern |
| Diagonal (45°) layout | 15% | Every edge tile requires angled cuts |
| L-shaped room or obstacles | 15% | More complex cuts around corners and columns |
| Herringbone or chevron | 20% | Complex pattern with many angled cuts |
| Mosaic or intricate patterns | 20%+ | High breakage rate, precise alignment needed |
Pro tip: After installation, store any leftover tiles in a dry place. Tile batches can vary in color and shade (called “lot variation”), so matching tiles from a different batch months later can be nearly impossible.
Tips for buying tiles
- Order 10% extra as a baseline. It’s cheaper to have a few extras than to reorder and risk a color mismatch.
- Buy all tiles at once. Even the same tile from the same brand can vary between production runs.
- Check the box count. Tiles are sold by the box, not individually. Divide your total by tiles-per-box and round up.
- Keep one full box stored after installation for future repairs.
Need to estimate grout?
Once you know how many tiles you need, the next step is figuring out how much grout to buy. Our Grout Calculator estimates the exact weight of dry grout mix required based on your tile size, joint width, and tile thickness — with optional bag and cost estimates.
- Consider the room shape. Simple rectangles waste less. Alcoves, columns, and angled walls all increase waste.
Frequently Asked Questions
Common questions about this calculator.
How much tile do I need?
Measure the length and width of your space, multiply them together to get the total square feet (or square metres), then divide by the area of one tile including the grout gap. For example, a 10 ft × 12 ft floor needs 120 sq ft of tile coverage. Our tile calculator does this automatically — just enter your dimensions, tile size, and preferred grout gap to get a precise count.
How do I calculate how many tiles I need?
First, measure the room's length and width in the same unit. Multiply to get the total area in square feet. Then calculate the effective size of each tile by adding the grout gap to both its length and width. Divide the room area by the tile's effective area and round up to the nearest whole number. Add 10–15% for waste from cuts and breakage. Our tile calculator handles every step of this process instantly.
How many square feet of tile do I need?
Measure the length and width of the area you want to tile in feet, then multiply them. For walls, measure the height and width of each wall section separately and add the results together. Don't forget to subtract areas like door openings if they won't be tiled. The tile calculator can convert between square feet and square metres automatically if you need metric measurements.
How much tile should I buy?
Order your calculated tile quantity plus a waste buffer — 10% for simple rectangular rooms, 15% for diagonal layouts or L-shaped spaces, and 20% for herringbone or chevron patterns. Tiles are sold by the box, not individually, so divide your total by the tiles-per-box and round up. Buy all your floor tiles or wall tiles from the same batch to avoid colour variation between boxes.
How many tile pieces do I need?
The total number of individual tiles depends on the tile size and your room's square footage. For instance, a 100 sq ft area needs exactly 100 pieces of 12×12 inch tiles (before waste), or 400 pieces of 6×6 inch tiles. Our tile calculator gives you an exact piece count after accounting for grout gaps and wastage, so you know precisely how many tiles to order.
How much tile do I need for a shower?
Measure each wall you plan to tile — multiply height by width for each section and add them together. A standard shower with three walls at 8 ft × 3 ft each needs roughly 72 sq ft of wall tile. Add 15–20% waste because shower installations involve many cuts around fixtures, corners, and niches. The tile calculator works for shower walls just as well as floors — enter your measurements for each surface separately.
How much wall tile do I need?
Measure the height and width of each wall you want to tile and multiply to get the square footage per wall. Add all wall areas together, then subtract any openings like windows or doors that won't be covered. For kitchen backsplashes, measure the length of the counter space and multiply by the desired height. Always add 10–15% for waste from cuts along edges and around outlets.
Do I need to include grout gaps in my calculations?
Yes. The grout gap slightly changes how many tiles cover a given area. A wider grout joint means each tile occupies more effective space, so you need fewer tiles overall. For most residential projects, the difference is small — typically 1–3 tiles per 10 square metres between a 2mm and 4mm joint. Our tile calculator accounts for grout gaps automatically, giving you an accurate count without manual adjustments.
How many tile spacers do I need?
You need roughly one spacer per tile edge, though the exact count depends on your layout. A quick estimate is to multiply the total number of tiles by 4, then divide by 2 since spacers are shared between adjacent tiles. For a 120 sq ft floor with 12×12 inch tiles (about 130 tiles with waste), expect to use around 260 spacers. It's wise to buy 10% extra since spacers can bend or break during installation.
How much extra tile should I buy for waste?
Plan for 10% extra tile for straightforward rectangular rooms with a straight-lay pattern. Increase to 15% for diagonal layouts, L-shaped rooms, or spaces with many obstacles. Use 20% for herringbone, chevron, or other complex patterns. Waste comes from edge cuts, breakage during handling, and pattern alignment. Our tile calculator lets you set a custom waste percentage so your order accounts for your specific layout.