How this calculator works
Adjusted area = length x width x waste allowance. Bags = adjusted area divided by bag coverage. Joint volume is estimated from paver size, joint width, and joint depth.
Polymeric sand coverage changes with joint width, joint depth, paver shape, and product type. Treat the bag count as a planning estimate and compare it with the manufacturer's chart.
The joint volume estimate helps you understand why wider or deeper joints consume significantly more sand than tight joints.
Polymeric sand bag examples
These examples assume 8x4 in pavers, 1/4 in joints, 1.5 in joint depth, 85 sq ft per bag, and 10% allowance.
| Project size | Adjusted area | Joint volume | Bags | Bag cost range |
|---|---|---|---|---|
| 10x10 ft | 110 sq ft | 1.17 cu ft | 2 | $50-$70 |
| 12x12 ft | 158 sq ft | 1.69 cu ft | 2 | $50-$70 |
| 12x16 ft | 211 sq ft | 2.25 cu ft | 3 | $76-$105 |
| 16x20 ft | 352 sq ft | 3.75 cu ft | 5 | $126-$175 |
Always compare this with the product coverage chart for your exact joint width.
Methodology and assumptions
- The default waste allowance is 10% to account for cuts, compaction, uneven excavation, and ordering buffer.
- Default base density is 1.6 tons per cubic yard; default driveway gravel density is 1.4 tons per cubic yard. Use your supplier's exact product density when available.
- Bag counts round up because partial bags are not orderable.
- Depth presets are planning defaults. Belgard describes a compacted aggregate base commonly between 4 and 6 inches for pavers, and CMHA describes bedding sand as a nominal 1 inch layer.
Example calculation
For the first row in the table, the calculator multiplies length by width, converts depth to a volume, adds the waste allowance, then converts that volume to bags, tons, or cost using the selected product assumptions.
This is a planning calculator, not an engineering specification. Confirm local code, soil conditions, drainage, and supplier product data before ordering.