How this calculator works
Area = length x width. Sand volume = area x bedding depth. Order volume = sand volume x waste allowance. Bags = order volume divided by bag volume.
Bedding sand should be screeded evenly and kept consistent. A thicker sand layer is not a substitute for a properly compacted base.
If your sand is sold in bags, update the bag volume from the packaging. If it is sold loose, use the volume result for bulk ordering.
This can also be used as a block paving sand calculator. In the UK, sharp sand or grit sand is often discussed for block paving bedding; in the US, the same layer is commonly called bedding sand or leveling sand. Always follow the paver manufacturer's product guidance.
Bedding sand examples
These examples use a 1 inch bedding sand layer, 10% allowance, and 0.5 cu ft bags.
| Project size | Sand volume | 0.5 cu ft bags | Bulk cost range | Area |
|---|---|---|---|---|
| 10x10 ft | 0.34 cu yd | 19 | $20-$28 | 100 sq ft |
| 12x12 ft | 0.49 cu yd | 27 | $29-$40 | 144 sq ft |
| 12x16 ft | 0.65 cu yd | 36 | $38-$53 | 192 sq ft |
| 16x20 ft | 1.09 cu yd | 59 | $64-$88 | 320 sq ft |
| 20x20 ft | 1.36 cu yd | 74 | $79-$110 | 400 sq ft |
Bedding sand should stay consistent; do not use extra sand to correct an uneven base.
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.