How to Measure a Room for Tiles

Measuring a room accurately is one of the most important steps when planning a tiling project. Ordering too few tiles can delay the installation if extra stock is needed, while ordering far too many may result in unnecessary expense.

Fortunately, measuring most rooms is straightforward. By following a few simple steps and allowing for wastage, you can estimate the number of tiles you need with confidence.

What You'll Need

Before you begin, gather the following:

• Tape measure or laser measure.
• Pen and paper.
• Calculator.
• A simple sketch of the room (optional but helpful).

Always measure in metres where possible, as tiles are usually sold by the square metre (m²).

Step 1: Measure the Length and Width

For a rectangular room, measure the longest length and the widest width.

Multiply the two measurements together.

This is the total floor area before allowing for wastage.

Step 2: Divide Irregular Rooms into Smaller Shapes

Many rooms are not perfect rectangles.

Instead of trying to calculate the whole room at once, divide it into simple rectangles or squares. Measure each section separately before adding the areas together.

This method improves accuracy and makes measuring easier.

Step 3: Decide Whether to Deduct Fixed Objects

Large permanent features such as chimney breasts or built-in cupboards can sometimes be deducted from the total area if they will not be tiled.

However, small areas occupied by toilets, vanity units or kitchen cabinets are often left within the calculation because cutting around them usually creates additional wastage.

If in doubt, it is generally safer to include them.

Step 4: Add Wastage

Very few tiling projects use every tile without cutting. Tiles may need trimming around walls, doorways, pipework, kitchen units, corners and obstacles.

Typical recommendations are:

• 5–10% for simple rectangular rooms with a straight lay.
• 10–15% for diagonal layouts, herringbone patterns or rooms with many cuts.
• 15% or more for complex layouts, large-format tiles or projects with intricate patterns.

Step 5: Check the Pack Coverage

Tiles are normally sold by the box, with each box covering a stated area.

Since tiles are sold in whole boxes, always round up to the next whole number.

Step 6: Keep Spare Tiles

Many professionals recommend keeping at least one unopened box of spare tiles after the installation is complete.

Spare tiles can be invaluable if:

• A tile is damaged.
• Alterations are made in the future.
• Repairs become necessary.
• The tile range is discontinued.

Finding an exact match several years later may be impossible.

Measuring Wall Tiles

The same principles apply to walls. Measure the width and height, then multiply the two measurements to obtain the wall area.

If tiling multiple walls, calculate each wall separately before adding the totals together.

Should You Measure Windows and Doors?

Large windows and doors can usually be deducted if they will not be tiled.

However, small openings often require numerous cuts around the edges, so many installers leave them within the calculation.

If you are unsure, allowing a little extra is generally preferable to running short.

Common Mistakes

Why It's Worth Double-Checking

Even experienced DIYers can overlook alcoves, chimney breasts, door recesses or unusual room shapes.

Many tile retailers will happily check your measurements before you place an order, helping to ensure you purchase the correct quantity while allowing for wastage.

Conclusion

Measuring a room for tiles is usually a straightforward process. By calculating the floor or wall area, allowing for an appropriate level of wastage and checking the coverage of each tile box, you can order with confidence and reduce the risk of delays during installation.

Taking a little extra time to measure carefully — and keeping a small number of spare tiles for the future — can save both money and inconvenience in the long run.