Gravel Calculator: Estimate Tons & Cubic Yards for Driveways & Landscaping
Free gravel calculator for driveways, walkways, and landscaping. Calculate cubic yards, tons, and weight for pea gravel, crushed stone, river rock, and sand. Includes compaction buffer and cost estimation.
Gravel Coverage Guide
Understanding Gravel Volume and Weight
- Volume Calculation:Rectangular: . Circular: . Triangular: (base ร height / 2 ร depth).
- Unit Conversion:Convert cubic feet to cubic yards by dividing by 27. One cubic yard equals 27 cubic feet.
- Weight Conversion:Multiply cubic yards by the material density (lbs per cubic yard) to get total weight in pounds, then convert to tons by dividing by 2,000.
Gravel estimation: volume (L ร W ร D), convert to cubic yards, then weight using material density. The calculator does all three and applies your compaction buffer.
Standard Material Densities
- Pea Gravel:2,400-2,800 lbs per cubic yard (1.2-1.4 tons). Best for patios, walkways, and decorative landscaping. Lighter weight makes it easier to spread.
- Crushed Stone:2,500-2,900 lbs per cubic yard (1.25-1.45 tons). Ideal for driveway bases and areas requiring good compaction. Angular edges interlock for stability.
- River Rock:2,600-3,200 lbs per cubic yard (1.3-1.6 tons). Heaviest option, excellent for drainage and erosion control. Smooth, rounded stones.
- Sand/Finings:2,600-3,000 lbs per cubic yard (1.3-1.5 tons). Used for bedding layers, leveling, and as a base for pavers. Fine texture compacts well.
Different gravel types have different densities, affecting both weight and coverage calculations.
Recommended Depths by Application
- Walkways:2-3 inches of gravel provides adequate coverage for foot traffic. Use pea gravel or crushed stone for best results.
- Driveways:4-6 inches minimum (3 inches absolute minimum for stability). Residential driveways typically use 4-6 inches, while commercial or heavy vehicle areas may need 6-8 inches.
- Drainage Areas:3-4 inches of river rock provides effective drainage while maintaining stability. Deeper layers may be needed for heavy water flow.
- Base Layers:4-6 inches of crushed stone or sand provides a stable foundation for pavers, concrete, or asphalt surfaces.
Proper depth ensures stability and prevents base layer exposure. Too little depth leads to failure; too much wastes material.
Understanding Compaction and Settling
Why Gravel Settles
- Vehicle Traffic:Cars and trucks compress gravel, causing 5-10% immediate settling. Over time, this can increase to 10-15% total compaction.
- Rain and Water:Water washes fine particles into gaps, causing additional settling. Proper drainage helps but doesn't eliminate compaction.
- Foot Traffic:Even pedestrian traffic causes gradual compaction, especially in high-traffic walkways.
- What this calculator does:Optional 12% compaction buffer adds extra material so you stay at target depth after settling.
Gravel compacts when driven on, walked on, or exposed to rain. This settling reduces the depth of your gravel layer over time, potentially exposing the base layer underneath.
Pro contractors typically add 10-15% to gravel orders. The default 12% buffer in this calculator is a safe middle ground.
Cost Estimation and Ordering Tips
Calculating Project Costs
- Price Per Ton:Gravel prices vary by location, material type, and quantity. Typical prices range from $15-50 per ton, with bulk orders often receiving discounts.
- Delivery Considerations:Factor in delivery costs, especially for large orders. Some suppliers offer free delivery for orders over a certain tonnage.
- Bulk Discounts:Ordering larger quantities often reduces the per-ton price. Calculate whether buying extra material for future projects is cost-effective.
Enter your supplier's price per ton to see total project cost. Handy for comparing quotes.
Ordering Best Practices
- Round Up:Always round up to the nearest 0.25 or 0.5 cubic yards. Suppliers typically deliver in these increments, and having a small buffer prevents short-orders.
- Consider Future Needs:If you have multiple projects planned, ordering in bulk can save money. Store excess material properly to prevent contamination.
- Verify Density:If using custom density, verify the actual weight per cubic yard with your supplier. Density can vary by source and moisture content.
Order in increments that match supplier capabilities and minimize waste.
FAQ
? How many tons of gravel are in a cubic yard?
Weight per cubic yard varies by material. Pea gravel: 1.2-1.4 tons (2,400-2,800 lbs). Crushed stone: 1.25-1.45 tons (2,500-2,900 lbs). River rock: 1.3-1.6 tons (2,600-3,200 lbs). Sand: 1.3-1.5 tons (2,600-3,000 lbs). The calculator uses these densities when converting volume to weight.
? What is the best gravel for a sloped driveway?
Crushed stone is the best choice for sloped driveways because it compacts well and provides excellent traction. The angular edges of crushed stone interlock when compacted, creating a stable surface that resists washout during heavy rain. For steeper slopes, use larger aggregate sizes (1-2 inches) and ensure proper drainage. Always apply a 10-15% compaction buffer to account for settling over time.
? How much gravel do I need for a driveway?
Residential driveways typically need 4-6 inches of gravel (3" minimum for stability); heavy traffic or commercial use calls for 6-8 inches. Volume = length ร width ร depth, then add 10-15% for compaction. The calculator converts to cubic yards and tons, with an optional compaction buffer.
? What is a compaction buffer and why do I need it?
A compaction buffer (10-15%) covers the settling that happens when gravel is driven on or rained on. Skip it and the layer thins over timeโyou risk exposing the base. Adding 12% keeps you at target depth. The calculator has an optional buffer (default 12%).