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How to Figure Out How Many Tiles You Need

How to Figure Out How Many Tiles You Need

Working out how many tiles to buy can feel a bit stressful the first time. You don’t want to under-order and get stuck halfway through, but you also don’t want ten boxes left over at the end. The good news is a tape measure, and a calculator will do the job.

Step 1: Measure the floor

 

If the room is a simple rectangle or square:

  • Measure the length
  • Measure the width
  • Multiply them together

So, a room 5m long and 4m wide = 20sqm. Easy.

If the room is shaped differently (like an L or has a nook), just break it into smaller rectangles, measure those and add them all up.

Step 2: Measuring walls (if you're tiling them)

 

Walls are basically the same formula.

  • Measure the height (or the height to where you want to tile to)
  • Measure the width
  • Multiply them together

If you’ve got more than one wall, do them one by one and then add them together.

Tip: Don’t forget to take out windows and doors. Example:

  • Wall = 2.5m high × 3m wide = 7.5sqm
  • Window = 1m × 1.5m = 1.5sqm
    So you only need to tile 6sqm.

 

Step 3: Add some extra (wastage)

 

Tiles aren’t like paint — you can’t use up every last bit. You’ll cut some, break some, and sometimes need extra to match a pattern. The safe bet is to add 15% more. If you’re laying something tricky like herringbone, bump that up to 20%.

Example: Room is 20sqm. Add 15% → 20 × 1.15 = 23sqm needed.

Step 4: If you're using more than one tile

 

Keep the maths separate. Floor tiles in one column, wall tiles in another. Add 15% on each. That way you won’t accidentally short one style and over-order another.

An example if a bathroom

 

  • Floor = 20sqm
  • Walls to 1m high = 17.1sqm (after subtracting door etc)
  • So floor tile total = 37.1sqm → with wastage = 42.7sqm
  • Upper walls = 22.8sqm (after subtracting window etc)
  • With wastage = 26.2sqm

And remember: tiles are sold in boxes, so round up to the nearest box.

Mistakes to avoid

 

  • Forgetting to allow for waste (most common).

  • Mixing metres and centimetres in the same calc.

  • Forgetting to subtract door/window areas.

  • Guessing instead of measuring properly.

Our advice

 

Always double-check your numbers. Seriously. Do it once, then do it again. If you’re planning a fancy layout, have a quick chat with your tiler before you buy. They’ll usually know if you need to allow a bit extra.

Once you’ve got your totals, you’re ready to shop — whether that’s our Everyday Essentials range or going for a Refined Luxury tile.

 

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