Gravel Calculator

How to Use This Calculator (Step by Step)

1. Choose your area shape — Select rectangular for driveways, patios, and pathways, or circular for round patios, fire pits, and landscape rings.
2. Enter dimensions — For rectangles, input length and width in feet. For circles, enter the diameter. Measure twice to confirm accuracy.
3. Set the desired compacted depth — Enter the depth in inches of compacted gravel you want to end up with. The calculator will automatically add material for compaction. For a residential driveway, 4–6 inches is typical. For a pathway, 2–3 inches is sufficient.
4. Select your gravel type — Choose the gravel size that matches your project. Each size has a different weight factor, which affects the ton estimate.
5. Adjust the waste factor — The default 10% covers minor spillage and uneven subgrade. Increase to 15% for irregularly shaped areas or sloped terrain.
6. Review results — The calculator shows compacted volume, loose volume (pre-compaction), tons, bag counts, and cost if you enter a price per ton or cubic yard.

How the Calculations Work

Understanding the math behind the calculator helps you double-check results and plan deliveries. Here are the core formulas:

• Area (rectangular): Length × Width = square feet
• Area (circular): π × (Diameter ÷ 2)² = square feet
• Compacted volume: Area × (Depth in inches ÷ 12) = cubic feet. Divide by 27 to get cubic yards.
• Compaction adjustment: To achieve a compacted depth of X, you need to order more loose material. The calculator divides by (1 − compaction factor). With the default 12% compaction factor, you order about 13.6% more loose material than the compacted volume.
• Tons: Cubic yards × weight factor. For example, 3/4" gravel at 1.65 tons per cubic yard: 5 cubic yards × 1.65 = 8.25 tons.
• Waste: The waste factor multiplies the loose quantity: Loose Volume × (1 + Waste%). A 10% waste factor on 8.25 tons gives 9.08 tons to order.

Example: A 20 ft × 12 ft driveway at 5 inches deep using 3/4" gravel with 12% compaction and 10% waste: Area = 240 sq ft. Compacted volume = 240 × (5/12) = 100 cu ft = 3.70 cubic yards. Loose volume = 3.70 ÷ (1 − 0.12) = 4.21 cubic yards. With 10% waste = 4.63 cubic yards. Tons = 4.63 × 1.65 = 7.64 tons. You would order approximately 8 tons.

Measuring Tips

• Measure length and width in feet using a tape measure or measuring wheel
• For irregular areas, break into rectangular sections and calculate separately
• Account for slope and drainage when determining depth
• Compact the sub-base before calculating gravel depth
• Order 5–10% extra for compaction and waste
• For circular areas, measure the diameter across the widest point
• Use a string line and stakes to mark straight edges before measuring

Gravel Size Guide

Choosing the right gravel size is critical for performance. Angular crushed stone locks together for stable surfaces, while rounded gravel is better for drainage and decoration. These weight factors are based on typical values consistent with ASTM D448 standard aggregate classifications.

Material Selection Guide by Project

• Residential driveway: Use a two-layer system. Start with 4 inches of #3 crushed stone (1–2 inch) as a base for drainage and load distribution. Top with 2–3 inches of #57 (3/4 inch) for a smooth driving surface. The angular edges of crushed stone lock together under vehicle weight, creating a self-reinforcing surface.
• Heavy-duty driveway (RVs, trucks): Increase total depth to 8–12 inches. Use #2 stone (2–3 inch) for the sub-base, #3 for the base, and #57 for the surface. Compact each layer in 3–4 inch lifts with a plate compactor.
• Garden pathway: 2–3 inches of pea gravel or #8 (3/8 inch) stone over landscape fabric provides a comfortable walking surface. Pea gravel is easier on bare feet but shifts more underfoot. #8 crushed stone stays put better.
• Patio base (under pavers): 4 inches of compacted 3/4-inch crushed stone (commonly called "traffic bond" or "Class 5") provides the standard base for patios and walkways. Top with 1 inch of leveling sand before laying pavers.
• French drain: Use 1–2 inch washed gravel (#3 or #4) around the perforated drain pipe. The large void spaces between stones allow water to flow freely. Avoid limestone, which can clog pipe perforations over time with fine sediment.

Common Mistakes to Avoid

• Ignoring compaction: Loose gravel settles 10–15% after compaction. If you order only the compacted volume, you will come up short. Our calculator accounts for this automatically when compaction is enabled.
• Using the wrong stone size: Smooth river rock does not compact and is a poor choice for driveways. Crushed angular stone is essential for any load-bearing surface.
• Skip the sub-base prep: Gravel laid on soft topsoil or mud will sink. Excavate to firm subgrade, compact the soil, and consider a geotextile fabric layer before placing gravel.
• Ordering by volume alone: Gravel is sold by weight (tons) at most quarries. Since weight-per-cubic-yard varies by stone size, always convert using the correct weight factor.
• Forgetting delivery access: A full dump truck needs at least 10 feet of width and adequate overhead clearance. Plan where the truck will dump to minimize wheelbarrow work.
• Underestimating depth for drainage: In wet climates or heavy clay soil, increase gravel depth by 2–3 inches to maintain proper drainage capacity year-round.

Tips for Best Results

• Install landscape fabric underneath to prevent weed growth and soil mixing
• Use edging (steel, plastic, or stone) to keep gravel contained and prevent spreading
• Compact each 3–4 inch layer before adding the next — a plate compactor rental is worth the $60–$80/day cost
• Consider drainage patterns when planning depth — slope surfaces away from structures at 1/4 inch per foot
• Order from local suppliers to reduce delivery costs — hauling gravel more than 20 miles adds significantly to the price
• Water the gravel lightly during compaction to help the stone settle and lock together
• For large projects, order 10–15% extra and stockpile the remainder for future maintenance and top-ups

Pro Tips for Contractors

• Always quote gravel by the ton, not cubic yard — the customer pays for weight, and it eliminates disputes about compaction and fluff factor.
• Use a laser level or transit to establish consistent depth across large areas before gravel placement. Uneven subgrade leads to thin spots that fail under load.
• On commercial jobs, request a gradation report from the supplier to verify the stone meets project specifications. This is standard practice informed by ASTM D448 and ASTM C33 guidelines.
• For driveway installations, schedule base layer delivery first, compact it, then schedule top layer delivery. This prevents contamination of the surface stone.
• Keep a stockpile of #57 stone on the truck for minor grade adjustments — it is easier to add material than to remove and relay.
• When estimating for clients, include a line item for geotextile fabric and edging. These add $0.50–$1.50 per square foot but dramatically extend the life of the gravel surface.

Gravel Cost Guide

Gravel prices vary by type, region, and quantity. Bulk deliveries (10+ cubic yards) are significantly cheaper per yard than small orders or bags. These prices represent typical US averages and may vary by region and supplier.

Prices are approximate US averages (2024–2025). Delivery fees typically add $50–$150 per load.

Gravel Compaction Reference

Compaction reduces gravel volume as stone particles settle and lock together. The compaction factor depends on stone size, moisture content, and compaction method. These values are based on typical industry experience and are consistent with general principles found in ASTM D1557 compaction testing standards.

Always compact in lifts of 3–4 inches for best results. Deeper lifts do not compact uniformly at the bottom.