SamCalculator

Tile Calculator

Calculate tile quantity, material requirements, grout spacing, box count, and project costs instantly with advanced tile planning tools.

Tile Quantity Calculator

Quick start:

Tile size

Area to cover

Grout / gap spacing

negative = overlap

Box size (optional)

leave blank to skip

Waste allowance

Fill in the inputs above and press Calculate to reveal your tile quantity calculator results, live tile preview, and smart insights.

What is a tile calculator?

A tile calculator turns three simple measurements — the size of your tile, the area you want to cover, and the width of your grout joints — into everything you need to buy the right amount of material the first time. Instead of guessing, you get an exact tile count, the number of boxes to order, a realistic waste allowance for cuts and breakages, and a full project cost.

This planner goes well beyond a basic quantity estimator. It accounts for grout spacing (which subtly changes how many tiles you need), models six real-world laying patterns and the extra cutting each one demands, estimates adhesive and grout weight, and visualizes your tiled surface live as you type. Whether you are tiling a small bathroom or a commercial floor, the goal is the same: order confidently, waste less, and avoid both shortfalls and costly over-buying.

How tile quantity is calculated

Measure the surface

Find the area to cover. For a rectangle, multiply length by width; for an L-shape, split it into rectangles and add them. You can enter room dimensions directly or type a known total area in square feet or square metres.

Find one tile's footprint

Each tile occupies its own face area plus a share of the grout joint around it. The calculator adds the gap to the tile's length and width, so a 600 mm tile with a 3 mm joint really takes up 603 mm of floor per tile.

Divide and round up

Dividing the surface area by one tile's footprint gives the raw tile count. Because you can't buy part of a tile — or part of a box — the result is always rounded up to whole tiles and whole boxes.

Add a waste allowance

Cuts, breakages, and future repairs mean you should buy extra. A 10% allowance suits most straight layouts; diagonal and herringbone designs need 15% or more because every edge tile is trimmed.

3 ways to use this calculator

1

Buy the exact amount

Enter your tile size and room and get the precise number of tiles and boxes, with a smart waste margin built in — no more eyeballing it at the store.

2

Budget the whole project

Add a price per tile, per box, or per square metre and instantly see your material cost, the cost of the waste allowance, and total spend in your currency.

3

Compare laying patterns

See how a grid, running bond, diagonal, or herringbone layout changes the cutting effort and material you need before you commit to a look.

Tiling best practices

  • Always add a waste allowance — 10% for straight grid and brick layouts, 15% or more for diagonal, herringbone, and rooms with lots of corners, alcoves, or pipework.
  • Buy all your tiles in one order so they share a single dye-lot (batch number); tiles bought later can differ subtly in shade and size.
  • Measure each area separately for irregular rooms, then add the totals — never tile a complex floor from a single rough rectangle.
  • Keep at least a box of spare tiles after the job for future repairs; an exact-match replacement years later is usually impossible.
  • Confirm your grout joint width before ordering — wider joints slightly reduce the tile count but noticeably increase the grout you need to buy.

Why getting the quantity right matters

Tiling is one of the few home projects where buying the wrong quantity costs you twice. Order too few and the job stalls while you wait for a new delivery — often from a different batch that no longer matches. Order far too many and you've sunk money into boxes that sit in the garage for a decade. An accurate count, with a sensible waste margin, is the single best way to keep a tiling project on time and on budget.

Beyond the headline tile count, the details decide the final bill: grout joint width changes both the look and the material list, the laying pattern dictates how much you cut and discard, and the price basis (per tile, per box, or per square metre) determines how the showroom quote maps to your real area. Getting all of these right in one place is what separates a confident order from an expensive guess.

Real-life tiling projects

Bathroom tiling

Plan floor and wall tiles together, account for the bath, shower tray, and niche cut-outs, and add extra for the many small cuts a bathroom demands.

Kitchen flooring

Estimate large-format porcelain for an open kitchen and work out boxes and adhesive while leaving room for cabinet and island cut-outs.

Living room flooring

Cover a big open space efficiently with 60–80 cm tiles, minimising grout lines and keeping the box count and cost predictable.

Wall & backsplash

Calculate metro, subway, or mosaic wall tiles, including running-bond offsets and the trim around outlets and windows.

Outdoor patio

Size anti-slip pavers with wider grout joints for drainage and frost movement, and add generous waste for site cuts.

Terrace flooring

Plan rooftop or balcony tiling with the right joint width for expansion and a realistic allowance for perimeter cutting.

Commercial flooring

Scale the estimate to large retail or office areas, compare pattern waste, and keep tight control of box quantities and budget.

Swimming pool tiling

Estimate small pool and waterline tiles where grout coverage is high and precise quantities matter for matching batches.

Core tile formulas

Surface area

Length × Width

A 4 m × 3.5 m kitchen is 14 m². For L-shaped rooms, divide into rectangles, find each area, then add them together.

Tile footprint (with grout)

(Tile L + Gap) × (Tile W + Gap)

A 600 mm tile with a 3 mm joint occupies 603 × 603 mm = 0.3636 m² of floor — slightly more than its 0.36 m² face.

Tiles required

⌈ Area ÷ Footprint ⌉

14 m² ÷ 0.3636 m² ≈ 38.5, rounded up to 39 tiles. The grout joint means you need a touch fewer tiles than a no-gap estimate suggests.

Tiles with waste

⌈ Tiles × (1 + Waste %) ⌉

39 tiles with a 10% allowance = ⌈42.9⌉ = 43 tiles, covering cuts and breakages so the job never stalls.

Boxes to buy

⌈ Tiles with waste ÷ Tiles per box ⌉

43 tiles in boxes of 6 = ⌈7.17⌉ = 8 boxes (48 tiles), leaving 5 spares for future repairs.

Grout weight

((L + W) ÷ (L × W)) × Joint × Depth × 1.8

Per square metre, in millimetres and grams per cm³. Wider joints and thicker tiles both increase the grout you must buy.

Common tile calculation mistakes

1

Forgetting the waste allowance

Buying the exact tile count leaves nothing for cuts, breakages, or repairs. Always add 10–15% — running short mid-job often means a mismatched second batch.

2

Ignoring the laying pattern

A diagonal or herringbone layout cuts far more tiles than a straight grid. Using a flat 10% on a herringbone floor almost guarantees a shortfall.

3

Mixing up units

Tile sizes are usually in mm or cm, rooms in metres or feet. Entering 600 cm for a 600 mm tile throws the whole estimate off — keep each field in its real unit.

4

Buying loose tiles instead of boxes

Tiles ship by the box, so order whole boxes and check the dye-lot. Counting only loose tiles ignores how stores actually sell them.

How accurate is this calculator?

Every figure here uses the standard area-and-coverage maths that tile retailers, contractors, and quantity surveyors rely on: surface area divided by the tile's grout-inclusive footprint, rounded up to whole tiles and boxes, with a transparent waste allowance you control. The grout-weight and adhesive estimates use widely published coverage rates, and the pattern waste percentages reflect typical trade guidance for each layout.

Treat the results as an accurate planning estimate, not a substitute for a site survey. Real rooms have out-of-square walls, alcoves, and obstacles that change cutting waste, and manufacturers' coverage rates vary by product. For large or complex jobs, confirm the final order against your tile supplier's quote and your own measurements before buying.

Frequently Asked Questions

Divide the area you want to cover by the area one tile occupies, then round up. The calculator does this precisely: it adds your grout joint to each tile's length and width to find the tile's true footprint, divides your surface area by that footprint, rounds up to whole tiles, and adds a waste allowance for cuts and breakages. For example, a 14 m² kitchen tiled with 60 × 60 cm tiles and 3 mm joints needs about 39 tiles, or roughly 43 with a 10% allowance.

Tile calculations rest on three measurements: the tile size, the surface area, and the grout joint width. Surface area divided by the tile's grout-inclusive footprint gives the raw number of tiles, which is rounded up because you can't lay part of a tile. A waste allowance is then added for perimeter cuts and breakages, and the result is rounded again to whole boxes. Cost is the tile count multiplied by the price per tile, per box, or per square metre.

For a standard straight (grid) or brick layout, add 10% extra. Step up to 15% for diagonal and herringbone patterns, where almost every perimeter tile is cut, and for rooms with lots of corners, alcoves, or pipework. A simple square room with large tiles can get away with 5–7%, while small mosaics and intricate designs may need 15–20%. The waste also leaves spare tiles for future repairs from the same batch.

Grout spacing — also called the joint width — is the gap left between tiles that is later filled with grout. It is typically 2–3 mm for wall and large floor tiles, 3–5 mm for outdoor pavers, and wider for rustic or handmade tiles. The joint affects both the look and the quantities: wider joints slightly reduce the number of tiles (each tile plus its joint covers more area) but increase the amount of grout you need to buy. Entering a negative value models overlapping tiles, as on some roofs and cladding.

It varies by tile size and brand — there's no universal number. Large 60 × 60 cm porcelain tiles often come 3–4 to a box; common 30 × 30 cm floor tiles around 9–11; and small wall tiles many more. The box also usually lists the area it covers (for example 1.44 m²). Always check the specific product, enter the tiles-per-box figure in the Box mode, and the calculator will tell you exactly how many boxes to order and how many spare tiles you'll be left with.

The maths is exact for the numbers you enter — it uses the same area, footprint, and coverage formulas that tile retailers and contractors rely on, then rounds up to whole tiles and boxes with a transparent waste allowance you control. Real-world results vary a little because rooms are rarely perfectly square, alcoves and obstacles change how many tiles are cut, and manufacturers' adhesive and grout coverage rates differ by product. Use it for confident planning and budgeting, and confirm large orders against your supplier's quote.

Measure the floor's length and width and multiply them for the area (split L-shaped rooms into rectangles and add the parts). Enter that as room dimensions or as a total area, set your tile size and grout joint, and choose a waste allowance — 10% for a straight layout, 15% for diagonal or herringbone. The calculator returns the tile count, the number of boxes, and an optional cost. Don't subtract small fixtures like a toilet base; the waste allowance comfortably covers them.

Wall tiling works the same way as floors, but you calculate the area of each wall (height × width) and add them together, then subtract large openings such as windows and doors if they're significant. Enter the total wall area, your tile size, and joint width. Wall tiles often use a running-bond (offset) layout like metro tiles, so allow around 10% for cuts — more if you're tiling around lots of fittings, niches, or a window reveal.

Larger tiles (60 cm and up) cover ground quickly, leave fewer grout lines for a cleaner, more spacious look, and install faster — but they need a very flat substrate and produce bigger offcuts. Smaller tiles and mosaics follow curves and slopes, suit small or wet areas, and hide minor unevenness, but mean more grout, more spacers, and slower installation. As a rule, match the tile scale to the room: big tiles for open floors, smaller formats for compact bathrooms and feature walls.

Buy your full calculated quantity plus the waste allowance, and always round up to whole boxes — then keep the leftover tiles. Beyond covering cuts and the odd breakage during installation, those spares are your insurance for the future: if a tile cracks years later, an exact match from the original dye-lot is usually impossible to find, so a spare box from the same batch is worth keeping. One full box of spares after a typical job is a sensible target.

Related Calculators