Paving Calculator
Work out how many paving slabs you need.
Paving slabs
42slabs
- Area
- 15 m²
v1.0 · Reviewed September 2026
How this is worked out
The paved area is divided by the area of a single slab, multiplied by any waste allowance, then rounded up.
Worked example
- Area 5 m × 3 m
- Slab 600 × 600 mm
- No waste allowance
15 m² ÷ 0.36 m² = 41.7, rounded up
42 slabs
Assumptions and limits
- Joint widths are not deducted, which slightly overstates the number of slabs on large areas.
- Cut slabs around edges and curves usually need a waste allowance of around 5 to 10 per cent.