Paving calculator
Paving is sold by the square metre or by the pallet, but counting the pieces helps you check the delivery. The calculator adds waste for cuts at edges and curves.
Your measurements
Result
- Area to order (incl. waste)
- 21.60 m²
- Pavers needed
- 1,080 pcs
The sub-base and bedding layer are not included.
How the calculation works
- Area to order = paved area + waste (8% by default).
- Pavers = area to order ÷ area of one paver (20 × 10 cm = 0.02 m²), rounded up.
Worked example
For a 20 m² path with 8% waste you order 21.6 m². With 20 × 10 cm pavers (50 per m²) that is 1,080 pavers.
What the calculator assumes
- 8% covers cuts at edges, curves and around manhole covers.
When to adjust the result
- The base is not included: usually 15–25 cm of compacted sub-base and 3–5 cm of sand or grit bedding.
- Edgings are counted by the running metre, on both sides of the path.
- A path needs a 1–2% fall towards a drainage point so water doesn't stand on it.
Laying paving that stays level
The sub-base does the real work. For a footpath, 10–15 cm of compacted crushed stone is typical; for a driveway, considerably more. Compact in layers of about 10 cm with a plate compactor, and give the surface a fall of 1.5–2% away from the house so water drains off.
Edge restraints are essential — without kerbs or edging set in concrete, blocks gradually spread and joints open. After laying, brush dry jointing sand into the joints, compact with a rubber mat on the plate and top up the sand. Order 5–10% extra for cuts, more for herringbone patterns and curved edges.
Frequently asked questions
How many block pavers per m²?
50 for 20 × 10 cm blocks, about 11 for 30 × 30 cm slabs and about 6.25 for 40 × 40 cm slabs.
How much extra paving should I order?
About 5–10% for cuts; more for curved designs.
How deep should a patio base be?
About 10–15 cm of compacted sub-base plus 3–5 cm of bedding for foot traffic; driveways need a thicker sub-base depending on the soil.
Do I need a membrane under paving?
A geotextile between soil and sub-base helps stop them mixing and is recommended on soft ground. Plastic sheet is not suitable because it blocks drainage.