Formula
A piece’s area is its length times its width, in metres.
Pieces are the paved area times one plus waste, divided by the area of one piece, then rounded up.
Blocks use the same rule. A 200 × 100 mm block is 50 per square metre before waste.
Worked example
12 m² of 600 × 600 mm slabs, with 10% waste, is 36.7 slabs, rounded up to 37.
Assumptions
Slabs start at 600 × 600 mm, with 450 × 450 mm beside it. The slab example area is 12 m².
Blocks start at 200 × 100 mm. The block example area is 8 m², so switch mode and set the area before comparing that example.
The count is pieces. It does not include edge restraints, sand or a sub-base. Gravel and concrete slab are linked for the layers under the paving.
Checked
Checked 10 November 2026. Wickes lists Marshalls slabs at 450 × 450 mm and 600 × 600 mm. Bunnings lists an Anston 600 × 600 mm slab and a Brighton Masonry paver at 200 × 100 mm.