Calculate in the order the patio is built
Working through the list in build order keeps the calculation honest. Each step uses the same measured area, so a mistake in the measurement shows up once rather than being buried in four separate estimates.
- AreaMeasure the patio footprint where the excavation will be, and enter each shape separately.
- BaseArea × base depth, with a compaction allowance because the base is worked.
- Bedding sandArea × bedding depth. This is a thin screeded layer, so the volume is small but not zero.
- PaversArea divided by the paver module — size plus joint — then a waste allowance for cuts.
- Edge restraintPerimeter length, or the perimeter the shape allows, plus waste, converted to stock pieces.
- Shopping listEach item with the unit your supplier sells in, plus the total paver surface area ordered for cross-checking.
The 12 ft × 20 ft example
The inputs are ordinary: a single rectangular area, 6 in × 6 in pavers, a 1/8 in joint, a 6 in compacted base, 1 in of bedding sand and the default 10% waste allowance. The result below includes the complete shopping list the calculator produces.
12 ft × 20 ft patio, 6 in × 6 in pavers
One rectangular area with 6 in × 6 in pavers, a 1/8 in joint, a 6 in compacted base, 1 in of bedding sand and the calculator default 10% waste allowance.
Inputs
- Patio area
- 12 ft × 20 ft
- Paver size
- 6 in × 6 in
- Joint width
- 0.125 in
- Base depth
- 6 in
- Bedding sand depth
- 1 in
- Waste
- 10%
Results
- Area
- 240 sq ft22.3 m²
- Paver module size
- 37.516 sq inPaver size plus the joint, which is what the count is based on
- Pavers before waste
- 922
- Pavers to order
- 1015
- Paver surface area ordered
- 264 sq ft
- Base material
- 5.5 cu yd5.38 cu yd after the compaction allowance · 7.53 tons
- Bedding sand
- 1 cu yd1.1 tons at the sand planning density
- Edge restraint
- 70.4 linear ft9 pieces at 8 ft stock length
| Item | Quantity | Unit | Note |
|---|---|---|---|
| Pavers | 1,015 | pavers | 240 sq ft net area with 10% waste. |
| Paver base | 5.5 | cubic yards | 6 in depth with 10.000000000000009% compaction allowance. |
| Bedding sand | 1 | cubic yards | 1 in bedding layer. |
| Edge restraint | 70.4 | linear ft | — |
| Edge restraint pieces | 9 | pieces | 8 ft stock length. |
The paver count and the base volume are both large, but they are large in different units and on different lead times: pavers are usually a stocked product counted by the piece, while base and bedding are bulk materials priced by the cubic yard. Use the paver surface area ordered as the figure to quote if your supplier prices by the square foot, and treat the base line as the one most likely to grow if the subgrade turns out softer than expected.
How to read the shopping list
- Pavers are counted from the module, not the raw area, so the count already accounts for the joints between units.
- The paver surface area ordered is the net area plus waste. It is the number to use if your supplier sells pavers by the square foot rather than by the piece.
- Base material is shown in cubic yards after the compaction allowance, because that is how bulk aggregate is ordered.
- Bedding sand is a separate line in cubic yards, at the bedding depth rather than the base depth.
- Edge restraint appears as linear feet and as stock pieces, so you can buy whichever unit your supplier uses.
Three cross-checks worth doing by hand
A take-off is easier to trust when two of its numbers can be checked with simple arithmetic. These three take a minute each and catch most ordering mistakes.
| Check | How to do it | What a mismatch usually means |
|---|---|---|
| Pavers per square foot | Roughly four for 6 in × 6 in pavers, because the module is a little over 6 in once the joint is included | A different paver size, or a joint width entered as feet rather than inches |
| Excavation depth | Base plus bedding plus paver thickness should match the depth you are digging | A gradient or a step that has not been allowed for |
| Edge restraint length | Two lengths plus two widths for a rectangle | A shape entered as a measured area, where the calculator cannot derive a perimeter at all |
These checks confirm the arithmetic. They do not confirm the design.
Practical ordering notes for pavers
- Pavers are often sold by the pallet or the layer, so the piece count is converted into whatever unit the supplier uses at the counter.
- Keep a spare bundle for later repairs. Matching a paver colour years later is unreliable, and intact offcuts do not exist unless you kept them.
- Confirm the paver thickness the base depth was planned around: a thicker paver changes the finished level as well as the price.
- Base and bedding are heavy. Check that the delivery can be placed close to the work, or plan for transporting material between the pile and the excavation.
- Bedding sand is sold screened and often called by a regional name. Ask for bedding sand for pavers rather than sand in general.
Related planning pages
Keep going
- How to plan a paver patioShape, layers, falls and the planning sequence
- Sand products and what they are used forWhy bedding sand is not the same as leveling or play sand
- Paver base: purpose, depth and compaction
- What drives paver patio cost
- Open the Paver Calculator
- Open the Paver Patio Calculator
Try it: Paver Calculator
Plan pavers, base, bedding sand, edging and cost. Every number on this page came from the same engine, so you can replace the example figures with your own measurements and compare.
- Paver CalculatorPlan pavers, base, bedding sand, edging and cost.
- Paver Patio CalculatorBuild a complete patio material plan with printable quantities.
- Paver Base CalculatorEstimate compactable base material for patios and walkways.
- Sand CalculatorCalculate sand for paver bedding, leveling and landscaping.
Frequently asked questions
How many pavers do I need for a 12 × 20 patio?
It depends on the paver size and the joint. This example uses 6 in × 6 in pavers with a 1/8 in joint, and the calculator returns a count around a thousand pieces including waste. Choose a larger paver and the count drops; widen the joint and it drops slightly further.
How much base material do I need under pavers?
At the default 6 in compacted base over 240 sq ft, the calculator returns about five and a half cubic yards of base after the compaction allowance, which is a bulk delivery rather than a bagged purchase. Depth is the variable that matters: a walkway base is usually thinner than a patio base, and a driveway base is thicker still.
Does the joint width really change the paver count?
Yes, by more than people expect. The count is based on the paver plus the joint, so a 1/8 in joint increases the module area of a 6 in paver by roughly 4%. Over a whole patio that is a meaningful number of units, and the calculator flags joints above a quarter inch because the layout changes as well as the count.
What is the difference between the Paver Calculator and the Paver Patio Calculator?
They use the same engine. The Paver Patio Calculator adds patio-specific framing, a named project and printable quantities so a result can be added to Project Mode and printed as part of a plan. Use whichever framing matches how you think about the job.
Should I order bedding sand in bags or bulk?
A patio of this size needs bedding sand as a bulk volume; bagged sand becomes expensive and laborious well before this scale. Bags make sense for repairs and small walkways. The calculator shows both so you can see where the crossover is for your own project.
Method and limitations
Where this estimate stops being useful
This take-off converts a described build-up into purchase quantities. It does not specify the base depth your soil needs, the paver thickness a system requires, the sand gradation that suits a particular joint width, or the restraint detail at walls, steps and curves. It also cannot see a soft spot, a gradient or a drainage problem. Confirm product-specific and site-specific requirements with the supplier and, where the site is difficult, with a qualified professional.
The methodology page documents how volume, waste, compaction and purchase quantities are produced, and the about page explains what this platform does and does not do.