Paver Calculator – Pavers, Base, Sand and Edging for a Patio or Driveway
A dry-laid paver job is more than a pile of pavers. Underneath sits a compacted stone base and a screeded layer of bedding sand; between the pavers goes joint sand; around the outside runs an edge restraint; and before any of it you have to dig a hole of the right depth and get rid of the soil. This paver calculator turns the size of your patio, walkway or driveway into the whole shopping list, and draws the layout to scale so you can see the pattern and the cuts.
The layers of a sand-set paver job
From the top down: the pavers, a bedding sand layer about 1 in (25–30 mm) thick, a compacted base of dense-graded crushed stone, and the undisturbed subgrade. The dig depth is simply the three added together: dig = base + bedding + paver thickness. For a typical patio that is 4 + 1 + 2⅜ = 7⅜ in, assuming the finished paving sits flush with the lawn. Laying a geotextile fabric on clay before the base, and building in a slight fall (about 1–2%) away from the house so water drains, are both worth planning at this stage.
Base depth for patios vs driveways
Foot traffic needs less support than cars. Common guidance is about 4 in (100 mm) of compacted base for patios and paths and 8 in (150 mm or more) for residential driveways, with 60 mm (2⅜ in) or thicker pavers under vehicles. Soft clay, poor drainage and hard frosts all call for more. The base must be a dense-graded material, such as crusher run, road base, 21A or MOT Type 1, whose fines lock the stones together; clean single-size gravel will not compact.
Why the base overhangs the edge
The outer row of pavers and the edge restraint carry load right at the edge. If the base stops at the last paver, the edge has nothing to spread onto and slowly sinks. Most guides run the base about 6 in (150 mm) past the pavers on every free side. Along a house wall or an existing slab there is nothing to support, so the calculator leaves out both the overhang and the edging on any side you mark as against a wall.
Compact the base, screed the sand
Base stone is spread loose and compacted in lifts with a plate compactor, so you order extra: with the default 20% allowance, a 4 in finished base means spreading about 4.8 in loose. Bedding sand is the opposite. It is screeded flat between rails and not compacted before the pavers go down; the pavers are bedded into it when you run the compactor over the finished surface. Keep it thin: a sand bed thicker than about 1½ in lets pavers rock and rut, so fix low spots in the base instead.
Pavers per square foot and the joint
Each paver covers its own face plus half a joint on every side, so the count is area ÷ ((W + joint) × (L + joint)). A 100 × 200 mm paver with a 1/8 in joint gives about 4.43 pavers per ft² (47.8 per m² with a 3 mm joint). Always enter the actual size from the pallet label: a "4 × 8" paver is usually 100 × 200 mm, not a true 4 × 8 in.
Choosing a pattern and a waste allowance
The pattern doesn't change how many pavers cover the area, only how many you cut. Running bond, stack bond and basketweave usually need about 5% extra, 90° herringbone about 10%, and 45° herringbone 15%, since every edge paver is cut on a diagonal. Curves add more. Herringbone and basketweave only close up when the paver is twice as long as it is wide plus one joint, which is why the classic 4 × 8 is so popular. Herringbone also interlocks best under turning cars.
Polymeric vs kiln-dried joint sand
Polymeric sand contains a binder that hardens when wetted, resisting weeds, ants and washout; it needs dry pavers and careful clean-up. Kiln-dried jointing sand is fine, dry sand that flows into narrow joints and is topped up over time. Either way, the quantity depends on joint width, paver size and depth. If the bag has a coverage chart, use it.
Edge restraint
Without a restraint, sand-set pavers creep outward. Plastic paver edging is spiked into the base about every 12 in; concrete edging kerbs are bedded and haunched in concrete. Cut-outs such as planters and tree pits need edging too.
Planning the dig and soil removal
Excavated soil bulks up by roughly 20–30% once dug, so size your skip, dumpster or trailer on the loose figure. The calculator shows both the in-place and loose volume for the whole base footprint.