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Paver Calculator: How Many Pavers, How Much Sand and Edge Restraint You Need
Work out how many pavers, how much bedding sand and how much edge restraint your paved area needs from area and paver size, with ICPI/ASTM sourcing.
ASTM C936 sets no paver length or width — it only bounds surface area (101 in² max), aspect ratio (length ÷ thickness ≤ 4) and minimum thickness (60 mm). Enter your own paver's dimensions.
ASTM C936 sets no paver length or width — it only bounds surface area (101 in² max), aspect ratio (length ÷ thickness ≤ 4) and minimum thickness (60 mm). Enter your own paver's dimensions.
ICPI Tech Spec 10: joints between concrete pavers are typically 1/16 to 3/16 in. (2 to 5 mm) wide — 1 to 2 mm wider for units in pedestrian areas with a stone like finish with rough edges and sides.
ICPI Tech Spec 10: bedding sand should be screeded to 1 to 1 1/2 in. (25 to 40 mm) uncompacted, consistent thickness — a recommended laying depth, not an ASTM norm. The same source: 'Do not use the sand to fill depressions in the base.'
A targeted search over cmha.org and icpi.org found no percentage figure for paver waste — 0 % is a starting point, not a claim that no cutting loss occurs.
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How the number is worked out
The steps from input to result
Concrete pavers are bought and laid by the piece, not by the square foot, so the number that matters at checkout is how many pavers a given area needs — including the joint between them, not just the bare paver footprint. Skipping the joint in the math buys too few pavers, especially with small paver formats.
ICPI Tech Spec 10, the CMHA application guide for interlocking concrete pavements, states that interlocking concrete pavers made by ICPI members typically meet ASTM C936, which defines concrete pavers as having a surface area no greater than 101 in.2 (0.065 m2), an aspect ratio no greater than 4, and a minimum thickness of 2 3/8 in. (60 mm). The standard sets neither a paver's length nor its width, so this calculator asks for both.
The same source specifies that bedding sand should be screeded to 1 to 1 1/2 in. (25 to 40 mm) uncompacted, consistent thickness — a recommended laying depth, not an ASTM norm — and warns: "Do not use the sand to fill depressions in the base."
Edge restraints are, in the source's own words, essential to the performance of an interlocking concrete pavement — the pavers and sand are held together by them. This calculator reports the perimeter of the paved area as a running-foot figure for that reason, rather than leaving it out.
The formula
Written out, so you can check it by hand
Pavers needed = round up( (area length × area width ÷ ((paver length + joint) × (paver width + joint) ÷ 144)) × (1 + waste ÷ 100) ); Bedding sand needed (ft³) = round up to the shown decimal( area length × area width × bedding sand thickness ÷ 12 ); Edge restraint needed (ft) = round up( 2 × (area length + area width) )
Worked example
Worked with the preset values
A 20 ft × 10 ft area (200 sq ft) with 8 in × 4 in pavers, a 0.125 in (⅛ in) joint, 1.25 in bedding sand and no waste allowance: each paver's footprint including its joint is (8 + 0.125) × (4 + 0.125) = 33.515625 in², or 33.515625 ÷ 144 ≈ 0.232747 sq ft. 200 ÷ 0.232747 ≈ 859.30, which rounds up to 860 pavers. Bedding sand is 200 × 1.25 ÷ 12 ≈ 20.8333 ft³ — rounded up to the shown decimal, never down, to 20.9 ft³. Edge restraint is 2 × (20 + 10) = 60 running ft.
What this calculator does not do
Named, not left out
- 01The recommended paver thickness by application (2 3/8 in./60 mm for pedestrian and residential driveways, 3 1/8 in./80 mm for vehicular traffic, 4 in./100 mm for heavy-duty commercial, 5 in./120 mm for the heaviest loads) is a buying guide only — it has no effect on this calculation, because paver thickness does not change how many pavers cover a given area.
- 02ICPI Tech Spec 10 states that cut pavers exposed to vehicular traffic should be no smaller than one-third of a unit — this calculator names that rule but does not count cut pieces.
- 03The ASTM C936 aspect ratio limit (paver length ÷ thickness ≤ 4) is not checked here, because this calculator does not ask for paver thickness.
- 04This calculator assumes a rectangular paved area (length × width) — an L-shaped area, a circle, or multiple separate areas are not supported; the edge restraint figure in particular depends on this rectangular assumption.
- 05No cut-piece count is produced — see the vehicular-traffic rule above.
- 06Bedding sand is reported in cubic feet only — neither source names a bag or ton conversion for it.
- 07One paved area per run — projects with multiple separate areas need to be run separately for each.
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Updated: 9/9/2026