Paver Sand Calculator: Bedding, Joint Sand and Cost
This paver sand calculator works out how much bedding sand goes under the pavers and how much joint sand goes between them. Enter the area, sand depth, and joint width, and it returns volume, weight, bulk bags, and total cost.
Sand is the quiet cost of a paver job. The pavers get all the attention, but the sand underneath and between them decides whether the patio stays level and whether the joints hold. This paver sand calculator covers both. It takes the area you’re paving, the sand depth, the compaction factor, and the joint width, then works out bedding sand, joint sand, and the bags or bulk weight you need to order. It handles rectangles, L-shapes, and direct area entry.
How to Use the Paver Sand Calculator
Pick the unit system: imperial (ft, ft², lb) or metric (m, m², kg).
Choose the area shape: rectangle, L-shape, or direct area.
Enter the dimensions. For a rectangle, type length and width.
Set the number of identical areas if you have more than one.
Pick the sand application: bedding, leveling, both bedding and joint, or joint only.
Enter the bedding sand depth, compaction factor, and waste factor.
For joint sand, set the joint width, paver size, joint depth, and coverage per bag.
Add your prices for bedding sand, joint sand, and labor.
The Summary tab leads with total sand weight and bag counts. Detailed Breakdown lists every volume and weight behind the result.
How the Paver Sand Calculator Formula Works
The calculator separates bedding sand from joint sand. Each has its own volume calculation.
Formula: Area = Length × Width (rectangle) or (Overall area − Cutout area) for L-shape
Formula: Bedding volume (compacted) = Area × Sand depth
Formula: Bedding volume (loose) = Compacted volume × (1 + Compaction %) × (1 + Waste %)
Formula: Bedding weight = Loose volume × Sand density
Formula: Bulk bags = ⌈ Bedding weight ÷ Bag weight ⌉
Formula: Joint area fraction = 1 − (Paver L × Paver W) ÷ ((Paver L + Joint W) × (Paver W + Joint W))
Formula: Joint volume = Area × Joint area fraction × Joint type factor × Joint depth
Formula: Joint bags = ⌈ Area ÷ Coverage per bag ⌉
Bedding volume starts compacted, then loosens up. Base material and sand both compact, so you order more loose volume than the finished depth suggests. A 20% compaction factor means 20% more volume in the bag than in the ground.
Joint sand volume depends on the gap between pavers. The joint area fraction compares the paver’s face area to the module area (paver plus joint). The difference is the joint. Polymeric sand uses slightly less volume because it binds, so the tool applies a 0.95 factor. Coarse sand uses slightly more.
Density converts volume to weight. The default is 100 lb/ft³ (1,600 kg/m³), which matches most dry masonry sand. If your supplier publishes a different density, change it.
Worked Example: A 20 ft × 15 ft Patio
Say you’re laying a 20 ft by 15 ft patio. Bedding sand is 1 inch deep, compaction factor is 20%, waste is 10%. Sand density is 100 lb/ft³. Joint width is 0.125 in, paver is 8×4 in, joint depth is 1 in, coverage is 100 ft² per bag. Bulk bags are 50 lb. Costs: $5 per bulk bag, $25 per joint bag, $200 labor.
Area: 20 × 15 = 300 ft²
Sand depth: 1 in = 0.0833 ft
Bedding volume compacted: 300 × 0.0833 = 25.0 ft³
Bedding volume loose: 25 × 1.20 × 1.10 = 33.0 ft³
Bedding weight: 33 × 100 = 3,300 lb
Bulk bags: ⌈3,300 ÷ 50⌉ = 66 bags
Paver area: 8 × 4 = 32 in²
Module area: (8 + 0.125) × (4 + 0.125) = 8.125 × 4.125 = 33.52 in²
Joint area fraction: 1 − (32 ÷ 33.52) = 0.0452
Joint surface area: 300 × 0.0452 × 0.95 = 12.88 ft²
Joint depth: 1 in = 0.0833 ft
Joint volume: 12.88 × 0.0833 = 1.07 ft³
Joint weight: 1.07 × 100 = 107.3 lb
Joint bags: ⌈300 ÷ 100⌉ = 3 bags
Bedding cost: 66 × $5 = $330
Joint cost: 3 × $25 = $75
Material subtotal: $405
Labor: $200
Total: $605
Cost per ft²: $2.02
Sixty-six bulk bags of bedding sand and three bags of joint sand. The bedding sand is the big line item because the whole 300 ft² sits on it. The joint sand is small by comparison, since it only fills the gaps between pavers.