Paving Calculator Australia — Pavers, Sand & Cement
Area to pave
Paver size
Sand & cement bedding
Results
Pavers
Bedding — sand & cement screed
Area & coverage
How to calculate pavers and bedding in Australia
The number of pavers needed is the total area divided by the area of each paver (including joint allowance on two sides), then rounded up with a wastage percentage added. Bedding material for a dry-pack screed is calculated from the bed volume — typically a 4:1 sand-to-cement mix by volume. At 30 mm depth over the paved area, multiply by the area in m² to get the screed volume. Sand density is approximately 1,600 kg/m³ and cement approximately 1,500 kg/m³. Add 10% wastage for cuts on straight patterns; 15–20% for diagonal or herringbone layouts.
Paving calculator — FAQs
How deep should the sand bed be under pavers in Australia?
For residential concrete pavers on a compacted sub-base, a 25–40 mm compacted sand or dry-pack screed is standard. The most common specification is 30 mm. For natural stone and slate, 20–30 mm is typical. The sand should be compacted before laying pavers, so allow for a slightly deeper initial bed that will compact down — most screed sand compacts by roughly 10–15%. Always lay pavers on a stable, well-compacted base (typically 100–150 mm of compacted road base for driveways).
What is a standard paver size in Australia?
Common Australian concrete paver sizes include: 400 × 400 mm (very common for paths and entertaining areas), 450 × 450 mm, 600 × 300 mm (plank style), 600 × 600 mm (large format), and 230 × 115 mm (brick pavers). Natural stone sizes vary widely. Always buy pavers with all cuts planned — irregular areas often need 15% or more wastage for cut pieces at edges and corners.
Should I use sand or a sand-cement mix under pavers?
For pedestrian paving (paths, patios), coarse washed sand alone is acceptable and is the simplest option. A dry-pack sand-cement mix (4 parts sand : 1 part cement) gives a firmer, more stable bed that is less likely to wash out or shift — it is the better choice for driveways, heavily trafficked areas, or near water features where plain sand would erode. Do not use wet concrete as a paving bed — it makes future paver removal very difficult and can crack unevenly.
What joint width should I use between pavers?
Concrete and clay brick pavers: 10 mm joints are standard, filled with kiln-dried or polymeric sand. Natural stone (bluestone, granite, sandstone): 3–5 mm joints are typical for a tighter, more formal appearance. Larger format pavers (600 × 600 mm+) suit wider 10–15 mm joints proportionally. Polymeric jointing sand (available at Bunnings and landscape suppliers) is recommended for driveways as it hardens to resist insect and weed intrusion.
Do I need a permit to pave a driveway or path in Australia?
In most states, minor paving work on private property (paths, patios, small driveways) does not require a building permit. However, stormwater drainage requirements apply — paved areas must direct water to an approved drainage point and must not cause water to flow onto neighbouring properties. Some councils require a drainage plan for large impervious areas. If connecting to a stormwater system, a licensed plumber may be required in some states. Check with your local council before any large-scale paving project.
How to use this calculator
- Enter the paving area — measure length and width in metres. For irregular shapes, break into rectangles, calculate each separately and add them together.
- Enter paver dimensions — input paver length and width in millimetres (e.g. 400 × 400 mm or 230 × 115 mm for a brick paver). These are printed on the pallet or product spec sheet.
- Set the joint width — standard for concrete pavers is 3–5 mm; clay bricks traditionally use 10 mm joints; natural stone varies from 5–20 mm depending on the style.
- Enter wastage percentage — use 5–10% for a simple rectangular area; 10–15% for curves, angles, or complex patterns like herringbone.
- Set bedding depth — 30 mm sand bedding for pedestrian concrete pavers; 50 mm for heavier loads (driveways). Crushed rock sub-base is a separate material, calculated and ordered independently.
- Read the result — paver count, sand required in kg, and number of 20 kg premix bags.
Worked example: Patio 6 m × 4 m (24 m²), 400 × 400 mm pavers, 5 mm joint, 10% wastage, 30 mm sand bed. Paver count ≈ 166 (including wastage). Bedding sand ≈ 1,152 kg — approximately 58 × 20 kg bags. Order pavers in full pallet quantities; most suppliers provide 40–60 pavers per pallet.
Understanding your results
The calculator returns three materials: pavers (count), bedding sand (kg), and cement/premix bags. Sand quantity is calculated using a dry density of approximately 1,600 kg/m³ — typical for washed coarse sand used in paver bedding. The cement figure assumes a dry cement:sand blend for semi-dry bedding.
The paver count includes your nominated wastage. For straight rectangular areas, 5% is generous. For curves, angles, or herringbone and diagonal patterns, 10–15% is more realistic — every cut paver is wasted material.
The calculator covers bedding sand only — the compacted sub-base (road base or crusher dust) below it is typically 75–150 mm and must be ordered separately. Sub-base is the most important layer and must be correctly compacted before laying bedding sand.
Common mistakes: Confusing bedding sand with sub-base, ordering pavers in units rather than full pallet quantities (partial pallets often attract surcharges), and failing to account for edge restraints — soldier courses at the perimeter may be a different size.
Paving in Australia — preparation, laying and drainage
A well-constructed paved area can last 20–30 years with minimal maintenance. A poorly prepared one can fail within 12–18 months as pavers sink, shift or crack. The foundation work is everything — visible paving represents only the top layer of a four-layer system.
Sub-base preparation
Excavate to a depth of 150–200 mm for pedestrian paving (100 mm of compacted road base + 30 mm sand bed + paver thickness). For driveways, use 200–250 mm of compacted road base to handle vehicle loads. Remove all topsoil and organic material — organic material compresses and rots over time, causing subsidence. Compact the natural subgrade with a plate compactor before adding road base.
Lay road base in 75 mm lifts and compact each layer. An uncompacted sub-base is the single most common cause of paving failure in Australia. Compact to at least 95% standard Proctor density.
Laying the bedding sand
Use coarse washed river sand or manufactured sand — not fine beach sand, which does not compact well. Spread to a consistent 30 mm depth using screed rails. Do not compact the sand before laying pavers — once screeded, it should stay undisturbed. Lay pavers from a corner or string line, working across the area without stepping on the screeded sand.
Drainage and falls
All paved areas must be graded away from buildings. A minimum fall of 1:100 (10 mm per metre) is standard for pedestrian paving; driveways typically use 1:50. Failure to provide adequate fall results in water pooling, which in clay soils leads to paver sinking and in sandy soils to wash-out of bedding sand. In some councils, stormwater from new paved areas must be directed to an approved drainage point — check local council requirements.
Jointing and sealing
After laying, spread kiln-dried sand over the surface and compact with a plate compactor (fitted with a rubber pad to protect pavers) to consolidate the joint sand. Top up and repeat until joints are full. Sealing is optional but recommended for porous concrete pavers in staining-prone areas (near BBQs, pool areas). Use a penetrating sealer rated for exterior use.
Australian standards and references
- AS 3727.1:2016 — Pavements — residential (design and construction of residential paved areas including sub-base, bedding and joint sand requirements)
- AS/NZS 4455:2012 — Masonry units, pavers, flags and segmental retaining wall units (material and dimensional requirements for pavers sold in Australia)
- AS 4456:2003 — Masonry units and segmental pavers — methods of test
- NCC Volume Two — Stormwater drainage requirements for residential construction
- Local council development controls — Most Australian councils regulate the extent of impervious surfaces on residential lots and may require stormwater management plans for large paved areas
- Concrete Masonry Association of Australia (CMAA) — Segmental paving design and construction guide