Paver calculator for patios, walkways and driveways

How the paver calculator works

The number of pavers is the area divided by the face of one paver, plus an allowance for cuts and breakage: a 4 × 8 in paver covers 32 square inches, so 4.5 pavers per square foot. The default allowance is 10%, the share that Nicolock, a paver manufacturer, puts down to border cuts, pattern offcuts and breakage.

Two layers go under the pavers. The base is area × compacted depth. Its weight comes from compacted material: research for the Wisconsin Department of Transportation (WisDOT) measured dense graded base at 1.78 to 1.98 tons per cubic yard once compacted, and the calculator uses 135 lb per cubic foot (1.82 tons per cubic yard). Loose in the truck, the same base takes 34 to 52% more room, so the volume to order adds 35%.

Bedding sand is spread loose, so it is simply area × depth at 97 lb per cubic foot of dry sand (Engineering ToolBox). Joint sand comes from the length of the joints: a 4 × 8 in paver gives 4.5 ft of joint per square foot, times the paver thickness and the joint width. Densities, the loose allowance, paver thickness and joint width are in the advanced options.

A worked example

In feet and inches (US). The calculator opens with a 12 × 12 ft patio, 4 × 8 in pavers 2 3/8 in thick, 4 in of base, 1 in of sand and 10% extra.

• Area: 144 sq ft
• Pavers: 144 ÷ (32 ÷ 144) = 648, plus 10% makes 713 pavers (158.44 sq ft)
• Base: 144 × 4/12 = 48 cu ft, or 1.78 cu yd compacted, 6,480 lb (3.24 tons); 2.4 cu yd loose, so 2.5 cu yd to order
• Bedding sand: 144 × 1/12 = 12 cu ft, 1,164 lb, or 24 bags of 50 lb
• Joint sand: 130 lb, 3 bags of 50 lb
• Digging depth: 2 3/8 + 1 + 4 = 7 3/8 in below the finished surface

For a driveway the base goes to 6 in: 2.67 cu yd compacted, 4.86 tons, 4 cu yd loose to order, and you dig 9 3/8 in.

In metres (UK and elsewhere). A 5 × 1.2 m path with 200 × 100 mm blocks, 100 mm of sub-base and 40 mm of sand: 6 m², 330 blocks, 0.6 m³ of compacted sub-base (1.29 t, 1 m³ loose to order), 15 bags of sharp sand at 25 kg and 2 bags of kiln-dried sand. Marshalls lays 50 mm of sand: write 5 cm in the sand field if you follow their guide.

How deep: base and sand for patios and driveways

Layer	Patio or walkway	Driveway	Source
Paver	2 3/8 in (60 mm)	2 3/8 in (60 mm)	CMHA
Bedding sand	1 in (25 mm), loose	1 in (25 mm), loose	CMHA
Compacted base	at least 4 in (100 mm)	at least 6 in (150 mm)	CMHA, well-drained soil
UK sub-base	at least 100 mm	at least 100 mm	Marshalls
Whole build-up in Germany	27-30 cm	30-50 cm	Rinn, from ZTV-Wegebau

The CMHA depths are minimums on well-drained soil: in colder climates and on wet or weak soils the base has to be thicker. The German figures count paver, bedding and base together and depend on how frost-susceptible the soil is. CMHA spreads and compacts the base in 4 to 6 in lifts with a plate compactor.

Buying pavers, base and sand

Pavers are sold by the piece, by the square foot or by the pallet, so the calculator gives both the count and the area. Rectangular pavers per square foot are 144 divided by the face in square inches.

Paver size	Per sq ft
4 × 8 in	4.5
6 × 6 in	4
6 × 9 in	2.67
12 × 12 in	1

For shaped pavers, use the coverage printed by the manufacturer and compare it with the receipt. Base gravel is sold in bulk by the ton or the cubic yard: the calculator rounds bulk up to the next half yard and shows the weight too, so you can order either way. CMHA asks for washed, sharp concrete sand under the pavers, never masonry sand or stone dust; the joints take fine dry sand, and CMHA notes that a stabilized (polymeric) joint sand helps where the sand tends to wash out.

Common mistakes

• Ordering base for the compacted depth. Guides give the depth after compaction; loose base takes at least a third more room.
• Levelling with the sand. CMHA warns that bedding sand must not make up for an uneven base: the dips show through the pavers later.
• Digging only for the base. The depth to dig is paver plus sand plus base, 7 3/8 in for the patio example.
• Using masonry sand or stone dust for bedding. CMHA rules them out: they do not compact evenly and slow the drainage of the bedding layer.
• Buying with no extra. Edges, curves and cuts around drains use up more pavers than you expect.