How to use the paver calculator
- Measure the patio or path length and width. For curves, measure the overall rectangle; the cut pieces are covered by the waste allowance.
- Enter the paver size and joint width. Many concrete pavers have small spacer nubs that set the joint for you.
- Set the waste: 5 to 10% for straight patterns, more for herringbone, curves and circles.
- Enter the base and sand depths. Patios and paths usually need less base than driveways.
- Add prices per paver and per cubic yard or cubic metre of base and sand.
How the materials are worked out
Base = area × base depth × (1 + waste %); sand = area × sand depth × (1 + waste %)
Edge restraint = 2 × (length + width)
The base weight uses about 1.6 tonnes per cubic metre for crushed stone, which helps when a supplier sells by the ton. The depths are compacted depths and the volumes are not increased for compaction. Loose crushed stone usually loses about 15 to 25% of its volume when compacted, so if your supplier sells by loose volume, raise the waste allowance or order that much extra base.
Worked example
A 12 × 10 ft patio laid with 4 × 8 in pavers, 1/8 in joints, 10% extra, a 4 in gravel base and 1 in of bedding sand, with pavers at $1 each:
- Area: 12 × 10 = 120 sq ft. Each paver with its joint covers 8.125 × 4.125 in = 0.2327 sq ft.
- Pavers: 120 × 1.10 ÷ 0.2327 = 567.1, so 568 pavers.
- Base: 120 sq ft × 4 in × 1.10 = 44 cu ft, or 1.63 cu yd (about 2.2 tons).
- Sand: 120 sq ft × 1 in × 1.10 = 0.41 cu yd, and the edge restraint runs 44 ft.
- Pavers, base and sand: $661.70.
Tips and common mistakes
- Dig deep enough. Excavation depth = base + sand + paver thickness. Skimping on the base is the main reason patios sink and rock.
- Compact in layers. Lay and compact the base in lifts of a few inches with a plate compactor, not all at once.
- Build in a slope. Give the surface a gentle fall away from the house, around 1/4 in per foot (about 2%), so water runs off.
- Hold the edges. Without a restraint along the edges, pavers creep outwards. Joint sand, often polymeric, locks them together.
- Locate services. Call 811 in the US (Click Before You Dig in Canada) before excavating.
US, UK and Canada differences
North American guidance commonly calls for about 4 to 6 in of compacted base under walkways and patios and more under driveways, with base and sand ordered by the cubic yard or ton. In the UK, the usual sub-base is Type 1 MOT, ordered by the tonne or in bulk bags, with sharp sand as the bedding layer, and block paving is sold by the square metre or pack. Canadian installers in cold regions often use deeper bases because of frost.
Metric units and other countries
In metric mode, paver sizes are in centimetres, joints in millimetres and base and sand depths in centimetres, with volumes in cubic metres. In places where tiles or interlocking pavers are sold per square metre rather than per piece, divide that price by the pavers per square metre on the label, or use the tile calculator. Type your local prices.