How to Calculate Paver Sand and Base Material
Two separate layers, each with its own depth and volume
Two layers, two calculations
A typical paver installation has a compacted base layer (crushed stone or road base, providing structural support and drainage) and a thin bedding sand layer directly under the pavers (for leveling). Each layer has a different, much smaller depth than the other, so they're calculated as two separate volumes.
Base layer depth
Base thickness is a design decision that depends on the soil and the traffic, so confirm it with the paver manufacturer, a local contractor or your project specification. The Concrete Masonry & Hardscapes Association (CMHA) guide specification recommends compacting the aggregate base to at least 98% standard Proctor density (ASTM D698) for pedestrian areas and residential driveways. The Road Base Calculator takes the finished, compacted depth and adds an allowance for the loose material you order.
Bedding sand depth
CMHA's guide specification screeds bedding sand to a nominal 1 inch (25 mm), using concrete sand that meets ASTM C33 grading — not stone dust or mason sand. It also says not to use bedding sand to fill low spots in the base; fix the base instead. Because the layer is thin, even a large patio needs much less sand than base.
Joint sand is separate
The sand swept into the joints after the pavers are laid is a separate, finer material, often polymeric sand. Order it separately; the Paver Sand Calculator sizes the bedding layer only.
Calculate each layer the same way
Both layers use area × depth, converted to cubic yards, exactly like a concrete slab volume calculation — just with two different depths for two different materials.
Worked Example
A 20 × 10 ft (200 ft²) patio with a 4 in compacted base (an example thickness — use your specification) and 1 in of bedding sand.
Base: 200 × (4/12) = 66.7 ft³ = 2.47 yd³
Sand: 200 × (1/12) = 16.7 ft³ = 0.62 yd³
With the calculators' 15% default allowances (calculator conventions): base ≈ 2.84 yd³ (Road Base Calculator), sand ≈ 0.71 yd³ (Paver Sand Calculator)
FAQ
- How much sand do I need under pavers?
- Bedding sand is screeded to a nominal 1 inch, so 100 ft² needs about 8.3 ft³, or 0.31 cubic yards, before any allowance. Joint sand is extra.
- What sand goes under pavers?
- CMHA's guide specification calls for concrete sand meeting ASTM C33 grading for the bedding layer, and says not to use stone dust or mason sand.
- How thick should the paver base be?
- It depends on the soil and the traffic, so take it from the paver manufacturer, a local contractor or your specification. Calculate it from the finished compacted depth and order loose material.
Related Calculators
Related Guides
From the Blog
Sources
NIST SP 811
Unit conversion reference (cubic feet, cubic yards, cubic metres).
NIST SP 811 — referenceCMHA PAV-TEC-009-13, Guide Specification for the Construction of Interlocking Concrete Pavement
Bedding sand screeded to a nominal 1 in (25 mm), ASTM C33 grading, no stone dust or mason sand, no filling of base depressions; base compaction to 98% standard Proctor for pedestrian areas and residential driveways.
CMHA PAV-TEC-009-13, Guide Specification for the Construction of Interlocking Concrete Pavement — reference