Wall Tile Calculator

How many tiles will you need?

For a kitchen wall measuring 4.5 m wide by 2.8 m high, using 300 × 600 mm wall tiles with a 5% waste allowance, you’ll need about 74 tiles. Buying too many wastes money; buying too few can mean a later batch doesn’t match. This wall tile calculator takes the guesswork out of the math.

Whether you’re tiling a kitchen, bathroom, or balcony, working out tile quantities is one of the first things to get right. This calculator factors in tile dimensions, grout joint width, and a cutting allowance to convert your wall measurements into the number of tiles to buy. It doesn’t replace a professional installer’s layout plan, but it gives you a solid estimate before you head to the tile store.

How to use this calculator

Open the Wall Tile Calculator and you’ll see a few input fields, each representing a real measurement. Here’s how to use them:

1. Enter the width of the wall you want to tile in the “Wall Length” field, in metres. For example, 4.5.
2. Enter the finished wall height in the “Wall Height” field, also in metres. For example, 2.8.
3. Enter the dimensions of your chosen tile in the “Tile Length” and “Tile Width” fields, in millimetres. Common sizes include 300 × 600 mm and 400 × 800 mm—just use the dimensions shown on the box.
4. “Grout Joint Width” defaults to 2 mm. Change it if you’re planning a tighter joint or a wider grout line.
5. “Waste Allowance” defaults to 5%, covering cuts and breakage during handling. If the wall has several windows or corners, or the tiles are more fragile, increase it to 8% or 10%.
6. Click the “Calculate” button. The results panel will immediately show the “Tiles Required” and “Recommended Purchase Quantity,” plus helpful figures such as total wall area and coverage per tile.

You can adjust any value and recalculate at any time—no manual formulas needed.

Worked example: calculating tiles for a kitchen wall

Let’s walk through a typical kitchen wall. Assume the wall is 4.5 m long and 2.8 m high, with 300 × 600 mm glazed wall tiles, 2 mm grout joints, and a 5% waste allowance.

Step 1: Calculate the total wall area.
Wall area = 4.5 × 2.8 = 12.6 square metres.

Step 2: Calculate the coverage area of one tile, including grout joints.
The tile measures 300 mm by 600 mm, with 2 mm joints. Since the grout joint adds to the space allocated to each tile, the effective tile length = 300 + 2 = 302 mm = 0.302 m, and the effective tile width = 600 + 2 = 602 mm = 0.602 m.
Coverage per tile = 0.302 × 0.602 ≈ 0.1818 square metres.

Step 3: Calculate the base tile quantity.
Base quantity = 12.6 ÷ 0.1818 ≈ 69.3 tiles, rounded up to 70 tiles.

Step 4: Add the waste allowance.
Quantity including waste = 70 × (1 + 5%) = 70 × 1.05 = 73.5 tiles, rounded up to 74 tiles.

Understanding the result: The calculator will show “Tiles Required: 74.” If tiles are sold by the box, divide this figure by the number of tiles per box to calculate how many boxes to buy. The 74 tiles include a standard allowance for cuts and offcuts. Increase the waste allowance if your wall has large angled sections or requires a decorative pattern.

Comparison example: a small bathroom wall

Now consider a bathroom wall measuring 2 m long by 2.4 m high, tiled with 200 × 200 mm small-format tiles, 3 mm grout joints, and an 8% waste allowance for the additional cutting.

• Wall area: 2 × 2.4 = 4.8 square metres.
• Effective tile length: 203 mm; effective tile width: 203 mm; coverage per tile: about 0.0412 square metres.
• Base quantity: 4.8 ÷ 0.0412 ≈ 116.5, rounded up to 117 tiles.
• Including waste: 117 × 1.08 ≈ 126.4, rounded up to 127 tiles.

Although this bathroom wall is only about one-third the size of the kitchen wall, it requires more individual tiles because the tiles are smaller, the grout joints are wider, and the waste allowance is higher. Use this calculator to quickly compare tile sizes and make a more informed choice.

Common use cases

Scenario 1: Shopping for tiles yourself. You’re standing in a tile showroom and a salesperson asks, “How large is the wall, and how many tiles do you need?” Open the calculator, enter the measurements for each room, and get an instant estimate for each tile option. It makes it easier to compare prices and stay on budget.

Scenario 2: Preparing a materials list. A contractor or tile installer can use the calculator to quickly double-check quantities before ordering materials—especially for non-standard wall sizes or areas using multiple tile formats. Calculate each section separately to reduce the time and cost of follow-up purchases.

Scenario 3: Creating a renovation budget video. Home-improvement creators can use the calculator to show how different tile sizes affect quantities and costs, helping viewers clearly compare whether large-format or small-format tiles offer better value.

Scope and limitations

This calculator is designed for rectangular walls tiled fully with one type of tile. Keep the following in mind:

• Door and window openings are not deducted. The calculator uses the full wall area. If openings are substantial, your actual tile requirement will be lower. Subtract their area from the wall area before entering an equivalent net wall size.
• Not suitable for complex layouts. Herringbone, chevron, diagonal layouts, borders, and decorative inserts can require far more than a 5%–10% waste allowance. This tool cannot calculate those precisely, so consult an experienced installer.
• Use the actual tile dimensions. A tile sold as “300 × 600 mm” may measure 298 × 598 mm in practice. The difference is small but can affect large installations, so use the working dimensions listed on the packaging for precise estimates.
• Results are estimates. Wall flatness, corner alignment, and cutting practices can all affect the final quantity. Consider buying one or two extra boxes as backup, especially for made-to-order tiles or styles that may be discontinued.
• Pattern matching is not included. If a tile pattern needs to align across the wall, waste will increase. Adjust the waste allowance accordingly.

Frequently asked questions

Q: Is the wall tile calculator accurate?
A: The calculation is accurate for the measurements and standard rectangular formula you enter, but real-world installation has variables. Treat it as a reliable estimate, then adjust for site conditions.

Q: Why is my installer’s estimate different?
A: Installers may deduct door and window openings, account for the final tile layout, or allow for more offcuts based on experience. Compare both estimates; if the difference is more than 10%, ask whether special factors have been included.

Q: What waste allowance should I use?
A: For a standard straight lay, 5% is usually enough. Use around 8% for walls with many pipes, corners, or windows. For small tiles, irregular shapes, or decorative patterns, allow 10% or more. If unsure, start at 5% and increase it based on the layout.

Q: How should I account for doors and windows?
A: This calculator does not have a separate field for openings. Measure their combined area and subtract it from the total wall area, then enter equivalent wall dimensions. For example, if your net area is 10 square metres, enter 5 m by 2 m to represent that area.

Q: Does grout joint width make much difference?
A: Increasing the grout joint from 2 mm to 5 mm slightly increases the space assigned to each tile, which can change the total by several tiles across a whole project. The effect is smaller with large tiles but matters more for small tiles or tight-joint installations. Enter the actual joint width you plan to use.

Q: How do I calculate a non-rectangular wall, such as one with a sloped ceiling or curve?
A: This calculator is for rectangular areas only. For a sloped wall, split it into rectangular and triangular sections, then estimate the triangle as half the area of its enclosing rectangle. For curved walls, consult a contractor because cutting waste can be much higher.

Try your own wall measurements in the calculator above to see exactly how many tiles you should buy.