Paver Calculator

Background.

A paver patio arrives in four separate deliveries: the pavers, crushed stone for the base, a thin layer of sand to bed them in, and a run of edging that stops the whole surface creeping outward. Each is sold in its own unit. Pavers come by the piece or the pallet, stone and sand by the cubic yard, edging by the length, and the yard itself is measured in feet. Most short orders happen in the conversion from one to another.

Take an 18 by 14 foot patio with a 12 by 3 foot path leading up to it. That is 288 square feet of finished surface. Add 7 percent for cuts and breakage, use a paver that covers half a square foot, and you need 617 pavers. If the supplier sells them 120 to a bundle, you buy six bundles, which is 720 pavers. Underneath, a 4-inch base comes to just over 4 cubic yards of stone once a compaction allowance is added, and an inch of bedding sand to a little under one cubic yard. Ninety-four feet of edging in 8-foot lengths is 12 pieces.

The rounding is where the money goes. Those 720 pavers cover 360 square feet, a full quarter more than the 288 you are paving, and the jump is set by the bundle size as much as by the waste allowance: with no waste at all, the same patio would need 576 pavers and five bundles, and it is the 7 percent that tips it into a sixth. Seeing that before you order lets you ask the supplier for a part bundle, or decide the 103 leftover pavers are worth keeping. Concrete pavers from a later production run rarely match the colour of the first exactly, so a small stack kept back is the easiest way to repair a cracked or stained unit years later.

What is paver calculator?

A segmental paver surface is built in layers. On top sit the pavers, most often 60 mm (about 2⅜ inches) thick for patios and paths. Beneath them is a screeded layer of coarse sand, usually about an inch, that the pavers are pressed into when the surface is vibrated. Below that is the base: compacted crushed stone that spreads the load onto the native soil and is the layer that decides whether the patio stays flat. Sand swept into the joints locks neighbouring pavers together, and an edge restraint holds the outside row in place. This calculator quantifies the pavers, the base, the bedding sand and the edging. It does not choose how thick the base should be. That depends on soil, drainage, frost and whether vehicles will drive on the surface, so it should come from the paver manufacturer, an installer or the project drawings. ASTM C936 is the US product standard for solid concrete interlocking paving units, and the Federal Highway Administration's tech brief describes permeable interlocking pavement, which swaps the sand layers for open-graded stone.

How to use this calculator.

1. 01Measure the main paved area as a rectangle and enter its length and width in feet. For an L-shaped patio, put the largest rectangle here; this section must be larger than zero.
2. 02Enter a path or second rectangle in the walkway fields (both dimensions must be above zero for it to count). Add any odd shape you have measured yourself, such as a round fire-pit pad, as a custom area in square feet, and enter as excluded area anything inside the outline that will not be paved: a tree pit, a fixed planter, a drain grate.
3. 03Enter the coverage of one paver from the product sheet. If the sheet lists pavers per square foot instead, divide 1 by that number: 4.5 per square foot is 0.2222 square feet each. Set the waste allowance; 7 percent suits a plain layout laid square to the edges, and diagonal patterns, curves and obstacles need more.
4. 04Enter how many pavers come in a bundle or pallet. If the yard sells loose pieces, enter 1 and the order will equal the paver count.
5. 05Enter the base depth and bedding sand depth in inches as specified, with an ordering factor for each (15 and 10 percent by default) to cover compaction and spreading loss. Measure only the edges that need restraint, leaving out runs along a house wall, a step or an existing slab, and enter the length of one edging piece.
6. 06Enter the price of one paver to get the paver material cost. The base, sand and edging price fields do not currently change any figure shown, so price those layers from the order volumes and piece count with your supplier.

The formula.

Everything starts from the net paved area: A = L₁ × W₁ + L₂ × W₂ + custom area − excluded area, held at zero if the exclusions are larger than the rest. The paver count is N = ⌈A × (1 + w) ⁄ aₚ⌉, where w is the waste allowance as a fraction (7 percent is 0.07) and aₚ the coverage of one installed paver in square feet; the ceiling brackets mean round up to the next whole paver. With a bundle size n, the order becomes ⌈N ⁄ n⌉ bundles, the ordered pavers are that many bundles times n, and the spare coverage is the ordered pavers times aₚ minus the waste-adjusted area A × (1 + w). Spare coverage therefore sits on top of the waste allowance rather than replacing it.

The two layers below are volumes. Base volume in cubic feet is A × d_b ⁄ 12, with the depth d_b in inches; dividing by 27, the exact number of cubic feet in a cubic yard (NIST Handbook 133), gives cubic yards, and multiplying by (1 + f_b ⁄ 100) applies the ordering factor. Bedding sand follows the same steps with its own depth and factor. Note that both layers use the net area A without the paver waste allowance, and without any strip of base carried past the paved edge, so their ordering factor is their only margin. Edging is ⌈E ⁄ ℓ⌉ pieces for an edge length E and piece length ℓ, and the paver cost is the ordered pavers, whole bundles included, times the unit price. The base, sand and edging costs follow the same pattern: the order volume in cubic yards times the price per cubic yard for base and sand, and the whole edge pieces times the price per piece for edging.

Because the count is rounded up twice, small changes in waste can cost nothing or a whole bundle. On the example patio, 7 and 10 percent waste both land on six bundles, while dropping to zero falls back to five. Check where the bundle boundary sits before you argue over a percentage point.

A worked example.

Frequently asked questions.

References& sources.

1. [1]ASTM International (2024). 'C936/C936M Standard Specification for Solid Concrete Interlocking Paving Units.' ASTM.
2. [2]Federal Highway Administration (2019). 'Permeable Interlocking Concrete Pavement.' FHWA-HIF-19-021.
3. [3]Belgard (n.d.). 'Paver and Wall Installation Guidelines.' Belgard.
4. [4]American Association of State Highway and Transportation Officials (2024). 'AASHTO Guide for Interlocking Pavements, 1st Edition.' AASHTO Store.
5. [5]National Institute of Standards and Technology (2023). 'NIST Handbook 133, Appendix E: General Tables of Units of Measurement.' U.S. Department of Commerce.