Sand Calculator
Estimate sand by area and depth, or convert cubic yards and tons with a density that matches your material.
FHWA typical dry unit weights are useful planning references. Use your supplier or lab bulk density when available, especially for wet, compacted, or specification-grade sand.
Use an allowance only when your project specification, supplier, or field conditions justify it.
How to Use
- Choose a calculation - estimate a project from dimensions, or convert cubic yards and tons directly.
- Enter the project size - use a rectangle or round area and the specified sand depth.
- Choose density - use an FHWA planning preset or enter the supplier or laboratory bulk density.
- Add extra only when needed - compaction, settlement, and field allowances are project-specific, so the default is 0%.
- Verify before ordering - confirm whether the supplier sells by weight or volume and whether the material is wet, loose, or compacted.
Sand does not have one universal yards-to-tons conversion because bulk density changes with gradation, compaction, and moisture. Using the calculator default of 99 lb/ft³ for loose well-graded sand, 1 cubic yard is about 1.34 US tons and 1 US ton is about 0.75 cubic yard. FHWA reference values for dry sand range from about 90 to 116 lb/ft³ depending on whether the sand is uniform or well graded and loose or dense. Use the supplier or lab density when you have it.
How Much Sand Do I Need?
For a project measured by area, calculate the sand volume first, then convert that volume to weight with the material's bulk density. The calculator above handles rectangular and round areas, so it works for patios, bedding layers, fill, sandboxes, and round pool-base layouts.
Density is the part that makes sand estimates less universal than plain geometry. FHWA lists dry unit weights from about 90 lb/ft³ for loose uniform sand to 116 lb/ft³ for dense well-graded sand, with saturated values higher. That is why a fixed rule such as "one yard always equals 1.35 tons" can be useful as a rough planning shortcut but should not replace the supplier's actual density. Sand is also used around above-ground pools - size the pool itself with the pool volume calculator.
Sand Coverage by Depth
Volume coverage is pure geometry. Weight coverage also depends on density. The per-ton figures below use the calculator default of 99 lb/ft³ (about 1.34 tons per cubic yard), so change the density in the calculator when your supplier provides a different value:
| Depth | Coverage per cubic yard | Coverage per US ton at 99 lb/ft³ |
|---|---|---|
| 1 inch | 324 sq ft | ~242 sq ft |
| 2 inches | 162 sq ft | ~121 sq ft |
| 3 inches | 108 sq ft | ~81 sq ft |
| 4 inches | 81 sq ft | ~61 sq ft |
| 6 inches | 54 sq ft | ~40 sq ft |
| 12 inches | 27 sq ft | ~20 sq ft |
For example, one cubic yard always covers 324 sq ft at 1 inch deep because the volume is fixed. A ton does not have fixed coverage: denser or wetter sand occupies less volume per ton, while looser dry sand occupies more.
How Sand Sits Under Pavers
FHWA Sand Density Reference
The calculator presets use typical dry unit weights published by the Federal Highway Administration. They describe sand condition and gradation, not retail product names:
| Sand condition | Dry unit weight | Approx. US tons per yd³ | Use in calculator |
|---|---|---|---|
| Uniform sand - loose | 90 lb/ft³ | 1.22 | Loose uniform preset |
| Well-graded sand - loose | 99 lb/ft³ | 1.34 | Default planning preset |
| Uniform sand - dense | 109 lb/ft³ | 1.47 | Dense uniform preset |
| Well-graded sand - dense | 116 lb/ft³ | 1.57 | Dense well-graded preset |
FHWA also reports higher saturated unit weights for these sands. Delivered material may be partially wet, saturated, compacted, or blended, so a supplier scale ticket or tested bulk density is more specific than a generic preset.
Formulas Used in This Calculator
The calculator keeps geometry and density separate so you can see where the conversion comes from:
Cubic yards = Volume (ft³) ÷ 27
US tons = Volume (ft³) × Density (lb/ft³) ÷ 2,000
Tons per yd³ = Density (lb/ft³) × 27 ÷ 2,000
Yards from tons = US tons ÷ Tons per yd³
The optional extra allowance is applied to project volume before the weight conversion. It is not applied in direct yards-to-tons or tons-to-yards conversion mode.
Septic Sand Calculator - Use the Approved Design
Septic mound, filter, and sand-lined systems are engineered and regulated locally. There is no safe universal table of "typical tons" by system type. Use the approved design dimensions or specified sand volume, then use this calculator only for quantity conversion:
| What the design gives you | Calculator mode | What to enter | What to verify |
|---|---|---|---|
| Footprint and sand depth | Project dimensions | Length/width or round area, then depth | Specified depth and material grade |
| Sand volume in cubic yards | Yards ↔ tons | Cubic yards | Supplier bulk density and selling unit |
| Required tonnage | Yards ↔ tons | US tons | Bulk density before converting back to volume |
| Gradation or sieve requirement | Not a quantity calculation | Use the approved specification | Supplier certification / local approval |
Some jurisdictions use ASTM C33 fine-aggregate gradation as part of their sand-fill requirements, while others add their own limits or equivalent gradations. The calculator cannot determine whether a material is approved for a septic system.
Septic Sand Density - No Universal Tons-per-Yard Number
A septic design may specify material gradation but still leave bulk density dependent on the actual source, moisture, and placement condition. For that reason, use the supplier or laboratory density when converting an engineered cubic-yard quantity to tons. The calculator's 99 lb/ft³ default equals about 1.34 US tons per cubic yard, but it is an FHWA loose well-graded sand planning value, not a septic-specific standard.
If an approved design calls for 50 cubic yards and the supplier confirms 100 lb/ft³ bulk density, the conversion is 67.5 US tons. If the supplier gives a different density, enter that value instead. This keeps the quantity calculation tied to the actual material rather than a universal wet-sand assumption.
Sources & Standards Notes
- FHWA lists typical dry unit weights of 90 lb/ft³ for loose uniform sand, 99 lb/ft³ for loose well-graded sand, 109 lb/ft³ for dense uniform sand, and 116 lb/ft³ for dense well-graded sand. Unit weight changes with density state and moisture.Federal Highway Administration - Geotechnical Engineering Circular / Chapter 5
- CMHA describes the bedding course for interlocking concrete pavement as nominally 1 inch (25 mm) and states that bedding sand should conform to ASTM C33 or CSA A23.1; mason sand should not be used as bedding sand.Concrete Masonry & Hardscapes Association - Application Guide / Construction Guidance
- Iowa DNR sand-mound guidance accepts ASTM C33 fine-aggregate gradation or a specified Iowa DOT gradation and adds limits on coarse fragments and fines, illustrating why septic sand must follow the approved local design rather than a generic material label.Iowa Department of Natural Resources - Sand Mound Design Guidance
- Georgia's current on-site sewage manual requires qualifying fill material to meet ASTM C33 fine-aggregate specifications with an additional limit on material passing the No. 200 sieve. Local requirements can differ by jurisdiction.Georgia Department of Public Health - Manual for On-Site Sewage Management Systems
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