liminfoTile Calculator
Free web tool: Tile Calculator
Net Area
20.0 m²
Tiles/m²
2.8
Total Tiles (w/ waste)
62
Grout (approx.)
6.0 kg
About Tile Calculator
The Tile Calculator estimates the total number of tiles required to cover a floor or wall surface, accounting for grout joints and a configurable waste allowance. You enter the room length and width in meters, the tile size in centimeters, the grout joint width in millimeters, and a waste percentage (typically 10%). The calculator computes the net area, derives tiles per square meter based on the effective tile size (tile dimension plus grout width), multiplies by the area to get raw tile count, and then adds the waste allowance to give you the total tiles to purchase.
This tool is used by homeowners planning bathroom or kitchen renovations, tile contractors preparing job quotes, interior designers estimating material costs, and project managers budgeting construction supplies. The grout width is factored into the effective tile footprint before calculating density — a 60×60 cm tile with a 3 mm grout joint occupies 60.3×60.3 cm per tile position, which affects tiles-per-m² and therefore the total count. Getting this calculation wrong leads to ordering too few tiles (causing project delays) or too many (wasting money).
Four common tile size presets (30×30, 45×45, 60×60, 30×60 cm) are provided for quick entry. The waste percentage defaults to 10%, which is the standard allowance for straight-lay patterns on regular room shapes. For diagonal patterns, curved walls, or rooms with many cuts, 15% or higher is recommended. The grout quantity estimate uses an approximation formula based on area, grout width, and a standard factor for typical tile thickness, giving you an estimate in kilograms of grout needed.
Key Features
- Calculates net room area from length and width inputs in meters
- Factors grout joint width into effective tile size for accurate tiles-per-m²
- Applies configurable waste percentage (default 10%) to the raw tile count
- Estimates grout quantity in kilograms based on area and grout width
- Four preset tile sizes: 30×30, 45×45, 60×60, and 30×60 cm
- Supports custom tile sizes by entering width and height separately
- Displays net area, tiles per m², and total tiles (with waste) simultaneously
- 100% client-side processing — no data sent to any server
Frequently Asked Questions
How many tiles do I need for a 5m × 4m room with 60×60 cm tiles?
With a 3 mm grout joint, each tile position is 60.3×60.3 cm = 0.363609 m². Tiles per m² = 1 / 0.363609 ≈ 2.75. For 20 m² (5×4), raw tiles = 20 × 2.75 = 55. With 10% waste: 55 × 1.1 = 60.5, rounded up to 61 tiles. The calculator performs this automatically.
What waste percentage should I use?
Use 10% for a straightforward rectangular room with a standard straight-lay pattern. Use 15% for rooms with multiple corners, alcoves, or L-shapes that require many cuts. Use 15–20% for diagonal patterns, herringbone patterns, or hexagonal tiles which generate more offcuts. When in doubt, use 15% — leftover tiles stored for future repairs are rarely wasted.
Why does grout width affect the tile count?
Grout width increases the effective spacing between tile centers, which changes how many tiles fit per square meter. A 3 mm grout joint on a 30×30 cm tile adds 30.3×30.3 = 918.09 cm² per tile position instead of 900 cm², reducing tiles per m² from 11.11 to 10.90 — a difference of about 2%. For small tiles or wide grout, the effect is more pronounced.
What is the grout quantity based on?
The grout estimate uses an approximation formula: area × 0.3 × (grout_width / 3). This is calibrated for standard-thickness floor tiles (approximately 8–10 mm thick) with a 3 mm grout joint requiring approximately 0.3 kg/m². Wider grout joints or thicker tiles require more grout. The estimate should be treated as a starting point — purchase slightly more than calculated to ensure you can complete the job.
Should I measure wall area differently from floor area?
The tile count calculation is the same for floors and walls — both use the same formula of net area divided by effective tile footprint. For walls, measure the height × width of each wall surface, subtract windows and door openings, and sum the areas. If different tile sizes are used on floors versus walls, calculate them separately.
What tile size presets are included?
The calculator includes four common presets: 30×30 cm (small bathroom/accent tiles), 45×45 cm (medium all-purpose tiles), 60×60 cm (large format floor tiles common in modern interiors), and 30×60 cm (subway-style rectangular tiles popular for walls). You can enter any custom size by typing values into the width and height fields.
How do I account for tiles cut at the edge of the room?
Edge cuts are automatically handled by the waste percentage. The 10% default covers typical edge cuts in a rectangular room. The calculator counts tiles needed to cover the full area mathematically — in practice, partial tiles at edges mean you cut full tiles and discard the off-cut, which is why the waste allowance is important. Do not try to measure partial tiles separately.
Can I use this calculator for wall tiles and backsplashes?
Yes. The calculator works for any flat surface — floors, walls, backsplashes, or outdoor patios. For a kitchen backsplash, measure the width of the backsplash area and its height, subtract any cabinet appliances or windows, and enter those dimensions as length and width. The same tile size, grout, and waste calculations apply.