Calculate Your Gravel
Proper gravel depth ensures durability and drainage. Driveway: 4-6", Patio: 2-4", Pathway: 2-3"
Gravel Type, Quantity, and Depth Reference
A gravel calculator is used to estimate cubic yards, tons, bags, and cost from length, width, depth, and material type. The key inputs are the project dimensions and the approximate weight of the gravel being ordered.
Common Gravel Types
- Pea gravel: decorative use, loose under traffic, about 1.4 tons per cubic yard.
- Crushed stone: common for driveways and base layers, about 1.5 tons per cubic yard.
- River rock: decorative drainage or bed material, about 1.6 tons per cubic yard.
- #57 stone: common base material, about 1.5 tons per cubic yard.
- Decomposed granite: pathway or patio material in dry climates, about 1.35 tons per cubic yard.
Gravel Volume Formula
(Length in feet x Width in feet x Depth in inches) / 324 = Cubic yards
Basic Steps
- Measure length and width.
- Choose the target depth.
- Convert depth and area to cubic yards.
- Multiply cubic yards by tons per yard for the selected gravel.
- Add a waste factor if the site is uneven or the gravel will compact.
Example
A 30-foot by 12-foot area at 4 inches deep equals 4.44 cubic yards. At 1.5 tons per cubic yard, that is about 6.66 tons before waste is added.
Typical Depth Ranges
- Pathways: 2 to 3 inches.
- Patios: 2 to 4 inches depending on base conditions.
- Driveways: 4 to 6 inches depending on traffic and climate.
- Drainage areas: 6 to 8 inches or as required by the drainage detail.
How Much Gravel Weighs
Weight varies by stone type, moisture, and source. The values below are planning references for dry material.
| Gravel Type | Tons/Cubic Yard | Lbs/Cubic Yard | Density |
|---|---|---|---|
| Pea Gravel | 1.4 | 2,800 | Low-Medium |
| Crushed Stone | 1.5 | 3,000 | Medium |
| River Rock | 1.6 | 3,200 | Medium-High |
| #57 Stone | 1.5 | 3,000 | Medium |
| Decomposed Granite | 1.35 | 2,700 | Low |
Bulk vs Bagged Gravel
Bulk gravel is usually the practical choice for larger projects. Bagged gravel is often used only for small repairs or small landscape areas. Delivery charges, minimum order size, and local supplier pricing can change the final cost more than the calculator alone.
Site Preparation Notes
- Area prep: remove grass, roots, and debris before spreading gravel.
- Grade: shape the base so water drains away from the finished surface.
- Compaction: compact the subgrade and any base layer before final placement.
- Fabric: non-woven landscape fabric may be useful where soil migration or weeds are a concern.
- Edging: perimeter edging helps contain gravel and reduce spread.
Maintenance Notes
Traffic, weather, and settling can reduce surface depth over time. Low areas may need topping off, and weed control or occasional regrading may still be required depending on the installation.
Gravel Reference Chart
| Application | Gravel Type | Recommended Depth | Cost/Ton | Compaction |
|---|---|---|---|---|
| Driveway | #57 Stone + Crushed Stone | 4-6 inches | $25-$40 | Excellent |
| Driveway (Budget) | #57 Stone | 4 inches | $20-$30 | Excellent |
| Patio Base | Crushed Stone | 2-3 inches | $25-$40 | Excellent |
| Decorative Patio | Pea Gravel | 2-3 inches | $30-$50 | Poor |
| Pathway | Pea Gravel or #57 | 2-3 inches | $25-$50 | Fair-Excellent |
| Landscape Bed | River Rock or Pea Gravel | 2-3 inches | $35-$65 | Poor-Fair |
| Drainage Area | River Rock or #57 Stone | 6-8 inches | $25-$50 | Fair |
Frequently Asked Questions
A 20 ft × 10 ft driveway at 4-6 inches deep needs about 2.5-3.7 cubic yards or 4-6 tons. Calculate your square footage, plug in 4-6 inches depending on your climate, and add 10% for settling. Use #57 stone or crushed stone—don't cheap out with pea gravel.
1.3 to 1.6 tons depending on type. Crushed stone and #57 run 1.5 tons, pea gravel is 1.4, river rock is 1.6, DG is 1.35. The calculator picks the right weight for whatever you select.
Two layers win every time: 3-4 inches of #57 stone as your base, then 2 inches of crushed stone or pea gravel on top. #57 locks together, stays put, and handles vehicle weight. Top layer is your choice based on looks. Never use pea gravel alone—it'll migrate into your garage by summer.
4-6 inches total. If you live somewhere with real winters and freeze-thaw cycles, do 6. Light use in moderate climates? 4 inches is fine. Compact the soil underneath first or it'll sink.
A truck holds 10-18 tons. Gravel runs $20-$50 per ton depending on type and location, so figure $200-$900 for the load before delivery. Delivery tacks on $40-$100. Call your local yard for actual pricing—it varies everywhere.
Crushed stone locks together and stays put—perfect for driveways. Pea gravel looks nice and feels good underfoot but doesn't compact, so it's best for pathways and decorative areas where cars won't be rolling over it.
