Enter your patio length and width and your paver or slab size, and get the number to buy plus the sub-base and bedding sand to lay them on. Works in metres/millimetres or feet/inches.
Paved area
20.0 sq ft
Gravel sub-base
0.62 yd³
Bedding sand
0.19 yd³
A paved area is three layers: pavers, set on a bed of sand, over a compacted gravel sub-base. The calculator sizes all three from your area:
paver footprint = (paver length + joint) × (paver width + joint)
pavers = ceil( area ÷ paver footprint × wastage )
sub-base = area × sub-base depth
bedding sand = area × bedding depth
Each paver is counted with one joint gap added on each side, so the joints are built into the number. Paving an L-shape or a patio plus a path? Add an area for each and the pavers pool into one order - an offcut from one edge can start the next run. Each area can be a rectangle, a circle (enter its diameter), or a right-angled triangle (enter the two legs), so curved and angled patios get a true area instead of a boxed-in guess. All math runs in exact metric internally, so switching units never changes the answer.
This example follows the unit system you pick in the calculator above.
A 16 × 13 ft patio in 8 × 4 in pavers with a ⅛ in joint, 10% wastage, over a 4 in sub-base and 1 in of bedding sand:
| Layer | Patio / path | Driveway |
|---|---|---|
| Pavers | 40-50 mm thick | 60-80 mm thick |
| Bedding sand | 25-40 mm (1-1.5 in) | 30-50 mm |
| Gravel sub-base | 100 mm (4 in) | 150-200 mm (6-8 in) |
Go deeper on any part of the job:
Divide the area you are paving by the size of one paver plus its joint, then add wastage for cuts. A 5 × 4 m patio in 200 × 100 mm pavers with a 3 mm joint and 10% wastage needs about 1,053 pavers; a 16 × 13 ft patio in 8 × 4 in pavers works out near 984. Enter your area and paver size above for the exact count.
Allow 100 mm (4 in) of compacted gravel sub-base under a patio or path, and 150-200 mm (6-8 in) under a driveway that takes vehicles. The calculator multiplies your paved area by the sub-base depth to give the volume - a 20 m² patio at 100 mm needs about 2 m³. Order a little extra, as it compacts down.
Pavers are laid on a screeded layer of sharp sand, usually 25-40 mm (1-1.5 in) thick. For a 20 m² patio at 30 mm that is about 0.6 m³ of sand. Set the bedding depth in the calculator to match how you are screeding; this is the laying course, separate from the jointing sand that fills the gaps.
The gaps between pavers are filled afterwards with kiln-dried or polymeric jointing sand, brushed in and compacted. Coverage depends on the joint width and paver depth, but a 20 kg bag typically fills the joints of roughly 5-15 m² - tighter joints and thinner pavers go further. Buy it by the bag once you know your area; this calculator sizes the pavers and the base.
Add about 5% for a simple running-bond or stack layout, 10% for offset or basketweave patterns, and 10-15% for herringbone or any 45-degree diagonal, where the perimeter cuts are more frequent. Round circles and curves waste more again. Pick the layout above and the calculator adds the matching allowance.
It depends on the paver size: about 50 standard 200 × 100 mm bricks per square metre (around 4.5 per square foot), 11 of a 300 × 300 mm / 12 × 12 in slab (1 per square foot), or roughly 6 of a 400 × 400 mm / 16 × 16 in slab. Those are nominal before joints and wastage - enter your exact paver size above for the real count.
Any of them. Set the paver length and width above to match your paver - a 200 × 100 mm brick or Holland block, a 16 × 16 in or 12 × 12 in concrete slab, a clay brick or a natural stone flag. The math is the same for concrete, brick and block pavers; only the dimensions change. For retaining wall blocks, note those are counted by wall face area, not floor area.
Build the material list first - pavers, gravel sub-base, bedding sand, jointing sand and edging from this calculator - price each line locally, then add labor, which is often half or more of an installed paver price. A driveway costs more than a patio of the same area because it needs a deeper base and thicker, vehicle-rated pavers. See the cost guide below for the full breakdown.
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