A paver patio is four orders, not one. The pavers are the part people count, and the three underneath them are where the job goes wrong: a compacted aggregate base, a screeded bedding course, and an edge restraint round the outside. This paver calculator does all four from the same measurements, including the compaction allowance that most estimates leave out.
What the layers are, and why they are ordered differently
The base is specified as a compacted thickness and sold loose, so the volume you order is larger than the layer you end up with. The bedding sand is the opposite: ICPI, now part of the Concrete Masonry and Hardscapes Association, specifies a nominal 1 inch screeded and left uncompacted, so what you order is what you spread. Treating both the same way is how a patio ends up an inch short of base and an inch deep in sand, which are the two classic failures.
- Base aggregate. ICPI puts patios and pedestrian areas at 4 inches minimum after compaction over well drained soil, and residential driveways at 6. Cold climates or weak soil want another 2 to 4 inches. How much paver base do I need works through the depths and the ordering in detail.
- Bedding sand. A nominal 1 inch, screeded, not compacted, and not used to level out a bad base.
- Pavers. Counted on the face plus one joint, because that is the space each one actually occupies.
- Edge restraint. The perimeter, in linear feet. Without it the outer row creeps and the joints open.
Why the paver count is not area divided by paver
A 4 by 8 paver measures 3.875 by 7.75 inches, and with an eighth inch joint it occupies 7.875 by 4 inches of ground. That is 0.219 square feet, or 4.57 pavers per square foot. Count the bare face instead and you get 4.8 per square foot, which is about five percent more pavers than the patio has room for. On 200 square feet that is 45 pavers of difference, most of a pallet.
The compaction allowance
Crushed stone loses roughly a fifth of its loose volume under a plate compactor. The specification is the compacted depth, the yard sells you loose material, and the gap between the two is the single most common reason a base finishes thin. The allowance is an input here rather than a constant, because it depends on the stone and how well it is compacted, but zero is the wrong answer.
What it does not count
Joint sand, the polymeric stuff swept into the gaps at the end, is a separate product bought by the bag and is not in these figures. Coverage depends on the joint width and the depth of the paver, and the bag tells you. Bedding sand and joint sand being different things, bought differently, is worth knowing before the delivery arrives.
Paver calculator FAQ
A 4 by 8 paver with an eighth inch joint occupies 0.219 square feet, so 4.57 pavers per square foot. A 12 by 12 paver works out at about 0.98 per square foot on the same joint.
A 200 square foot patio at the 4 inch compacted minimum takes 80 cubic feet of loose stone once a 20 percent compaction allowance is added, which is 2.96 cubic yards or about 4.4 tons. A residential driveway wants 6 inches rather than 4, which is half as much again, and cold climates or soft soil want another 2 to 4 inches on top of whichever applies.
One inch, screeded and uncompacted, which on a 200 square foot patio is 16.7 cubic feet, 0.62 cubic yards or about 0.83 tons. Deeper bedding is a common cause of settling rather than a fix for an uneven base.
