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.

Lifestyle 2 Bao Elegant 1500mm Back to Corner Bath - Matte White - Left Hand Corner BAO200215LM - The Blue Space

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 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.

Ingrain Curved Fluted Wall Hung Vanity 1500mm Double Basin in bathroom with green tiles at The Blue Space

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 of 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.

By Elise Pride

eCommerce Manager

05 November 2025

Elise is a design-focused content creator at The Blue Space, offering practical renovation advice and trend-led insights to help customers style their dream spaces with confidence.