Tile and Paving Calculator
Choose tiles or paving, enter the size of the area and of one tile or slab, and the joint width. You get the number to buy, and either the grout or the stone and sand underneath.
This is an estimate. Always check the coverage on the grout, adhesive and sub-base you buy.
Worked examples
A bathroom floor
5 square metres, 300 mm tiles, 3 mm joints, 8 mm thick, 10% waste
60 tiles and about 1.3 kg of grout
54.5 tiles are needed before waste.
A patio
20 square metres, 600 mm slabs, 10 mm joints, 10% waste, 100 mm base
60 slabs, 4.6 tonnes of stone, 0.96 tonnes of sand
The stone includes 10% for compaction.
About Tile and Paving Calculator
A tile calculator tells you how many tiles or paving slabs to buy for a floor, wall or patio. The number is the area to cover divided by the area one tile takes up, including its share of the joint, plus an allowance for waste. Enter the size of the area, the size of one tile and the width of the joint, and the tool does the rest.
For tiles it also estimates the grout, from the size and thickness of the tile and the width of the joint. For paving, switch to slabs to see the crushed stone sub-base and the sand bed that go underneath, in tonnes, which is how builders merchants sell them. Always buy a little extra, and from the same batch, because shades vary.
How to use Tile and Paving Calculator
- Choose wall or floor tiles, or paving slabs.
- Enter the size of the area, or the length and width, and take off any cut-outs.
- Enter the tile size and the joint width. Use the common sizes list to fill in the size.
- Read the number to buy. Tiles also give a grout figure and paving gives stone and sand.
Common uses
- Tiling a bathroom or kitchen floor
- A splashback or wall of metro tiles
- A new patio
- Comparing tile sizes
Frequently asked questions
How many 300 mm tiles do I need for 5 square metres?
With a 3 mm joint each tile takes up 0.0918 square metres, so 5 square metres needs 54.5 tiles. With 10% waste that is 60 tiles.
How much waste should I allow for tiles?
Allow 10% for a straight layout in a simple room and 15% or more for diagonal layouts, large tiles, or rooms with a lot of cuts. Natural stone varies, so more again.
How much grout will I need?
The estimate uses the tile size, thickness and joint width. 300 mm tiles that are 8 mm thick with a 3 mm joint use about 0.26 kg for each square metre, so 5 square metres needs about 1.3 kg. Use the guidance on the pack as well.
How much sub-base is needed for paving?
A patio normally has 100 mm of compacted crushed stone and a 30 mm sand bed. For 20 square metres that is about 4.6 tonnes of stone, including an allowance for compaction, and 1 tonne of sand.
Do I include the joint in the tile size?
No. Enter the tile size on its own and the joint separately. The calculator adds the joint to each side.