How to Calculate How Much Gravel You Need (Free Tool)

Why Getting the Amount Right Matters

Ordering too little gravel means a second delivery — another $50-150 delivery fee, another day waiting, and an unfinished project sitting in your yard. Ordering too much means paying for material you do not need, plus the hassle of figuring out where to put the excess. A single cubic yard of gravel weighs about 2,800 pounds. You cannot exactly toss leftovers in the recycling bin.

The difference between a correct estimate and a wrong one often comes down to a single calculation error: forgetting to convert inches to feet for the depth, miscalculating irregular areas, or not accounting for compaction. A calculator that handles the math correctly saves money and eliminates waste.

The Gravel Calculator on AllTools computes exactly how many cubic yards and tons of gravel you need based on your project dimensions. Enter the area dimensions and desired depth, and get an instant answer — no account, no app download, no guesswork.

The Gravel Calculation Formula

The basic formula for any fill material is:

Volume = Length x Width x Depth

For gravel specifically:

1. Calculate the area in square feet (length x width)
2. Convert depth from inches to feet (divide by 12)
3. Calculate volume in cubic feet (area x depth in feet)
4. Convert to cubic yards (divide cubic feet by 27, since 1 cubic yard = 27 cubic feet)
5. Convert to tons (multiply cubic yards by the material density factor)

Example: A driveway that is 40 feet long, 12 feet wide, and 4 inches deep:

• Area: 40 x 12 = 480 square feet
• Depth in feet: 4 / 12 = 0.333 feet
• Volume: 480 x 0.333 = 160 cubic feet
• Cubic yards: 160 / 27 = 5.93 cubic yards
• Tons (at 1.4 tons per cubic yard for crushed stone): 5.93 x 1.4 = 8.3 tons

Add 10-15% for waste and compaction. Gravel compacts when driven on or rained on, settling into the substrate below. For the driveway example, ordering 6.5 to 6.8 cubic yards accounts for this settling.

For quick area measurements before you start, use the Square Footage Calculator to handle rectangular, circular, and triangular areas.

Step by Step: Use the Gravel Calculator

Step 1 — Measure your project area. Use a tape measure for the length and width (or diameter for circular areas). For irregular shapes, break the area into rectangles, triangles, or circles, calculate each separately, and add them together.

Step 2 — Determine your depth. The required depth depends on the project type (see the depth guide below). Measure in inches — the calculator handles the conversion.

Step 3 — Open the calculator. Go to the Gravel Calculator. No login needed.

Step 4 — Enter dimensions. Input the length, width, and depth. Select your measurement units (feet/inches or meters/centimeters). For circular areas, enter the diameter instead.

Step 5 — Select gravel type. Different gravel types have different densities. Pea gravel weighs about 1.3 tons per cubic yard; crushed limestone about 1.4 tons; river rock about 1.35 tons. The calculator adjusts the tonnage based on the material you select.

Step 6 — Review the results. The calculator displays:

• Total volume in cubic yards and cubic feet
• Weight in tons and pounds
• Estimated cost based on typical material prices
• Recommended overage amount (10-15%)

Step 7 — Order your gravel. Call your local landscape supply or quarry and order by the cubic yard or ton, depending on how they sell. Most suppliers sell by the ton for bulk deliveries and by the cubic yard (or bag) for pickup orders.

Depth Guide: How Deep Should Your Gravel Be?

The right depth depends entirely on the application. Too shallow and the gravel will not perform its function. Too deep and you waste material and money.

Driveways: 4-6 inches (layered)

A gravel driveway needs a stable base that can support vehicle weight without rutting. The standard approach uses three layers:

• Bottom layer (2-3 inches): Large crushed stone (1.5 to 2.5 inch pieces) for drainage and stability. This is the structural foundation.
• Middle layer (2 inches): Medium crushed stone (0.75 inch) that locks into the base layer and provides a smoother surface.
• Top layer (1-2 inches): Fine gravel or crushed stone (0.375 to 0.5 inch) for a smooth driving surface.

Total depth: 5-7 inches before compaction, settling to about 4-6 inches.

Walkways and garden paths: 2-3 inches

Foot traffic requires less structural support than vehicles. A 2-3 inch layer of pea gravel or decomposed granite over landscape fabric provides a comfortable, stable walking surface. Use an edging material (metal, plastic, or stone) to keep the gravel contained.

Drainage areas: 6-12 inches

French drains and drainage channels need deep gravel beds to allow water flow. Use large, angular stones (1 to 2 inches) that create air pockets for water movement. The depth depends on the drainage volume required — a simple downspout extension might need 6 inches, while a full French drain system needs 12 inches or more.

Patio base: 4-6 inches

A gravel base under pavers or flagstone provides drainage and prevents frost heave. Crushed stone (not round gravel) compacts into a rigid base. Compact each 2-inch layer with a plate compactor before adding the next layer.

Decorative ground cover: 1-2 inches

For flower beds, around trees, or as decorative landscaping, 1-2 inches of gravel over landscape fabric suppresses weeds and retains moisture. This is the lightest application and uses the least material.

Gravel Types and Their Uses

Crushed stone (angular)

Machine-crushed rock with sharp, angular edges that lock together when compacted. This is the structural gravel — used for driveways, patio bases, and drainage. Available in sizes from 0.25 inch (stone dust) to 2.5 inches. Density: about 1.4 tons per cubic yard. Colors vary by source rock: gray (limestone), tan (sandstone), blue-gray (basalt).

Pea gravel (rounded)

Small, naturally rounded stones about 0.25 to 0.5 inch in diameter. Smooth and comfortable underfoot, making it ideal for walkways, play areas, and decorative ground cover. Does not compact well — not suitable for driveways or structural bases. Density: about 1.3 tons per cubic yard. Naturally multicolored (tan, brown, white, gray).

River rock (large rounded)

Larger rounded stones from 1 to 5 inches. Used for decorative landscaping, dry creek beds, erosion control, and drainage channels. Too large and round for walkways (uncomfortable and unstable underfoot). Density: about 1.35 tons per cubic yard. Often sold by color: white, gray, mixed earth tones.

Decomposed granite (DG)

Granite that has weathered into small particles. Creates a natural-looking, semi-hard surface that compacts into a firm walking surface. Popular for pathways in gardens, dog runs, and rustic landscapes. Available in gold, tan, brown, and red depending on the source region. Density: about 1.35 tons per cubic yard.

Limestone screenings

Fine crushed limestone (almost powder-like) used as a base under pavers, for leveling, and for filling joints between stones. Compacts extremely well. Also called “crusher run” when mixed with larger crushed stone for road bases.

Cost Estimates

Gravel prices vary by region, type, and quantity, but these ranges cover most US markets in 2026:

Delivery fees typically run $50-150 depending on distance and quantity. Most suppliers offer free delivery for orders above 10-15 tons. For smaller projects, picking up material yourself in a truck or trailer saves the delivery fee.

Bulk vs bagged: Bagged gravel from home improvement stores costs $4-8 per 0.5 cubic foot bag — roughly $200-400 per cubic yard. Bulk delivery costs $35-85 per cubic yard. For anything more than a small garden bed, bulk delivery is dramatically cheaper.

The Gravel Calculator provides cost estimates based on current typical prices, but always confirm pricing with your local supplier before ordering.

Calculating for Irregular Shapes

Not every project is a simple rectangle. Here are approaches for common irregular shapes:

L-shaped areas: Split into two rectangles. Calculate each separately and add the volumes together.

Circular areas: Use the formula: Area = pi x radius squared. For a 10-foot diameter circle: radius = 5 feet, area = 3.14 x 25 = 78.5 square feet. Then multiply by depth and convert as usual.

Triangular areas: Area = 0.5 x base x height. For a 12-foot base and 8-foot height: area = 0.5 x 12 x 8 = 48 square feet.

Curved paths: Approximate the curve as a series of short straight segments, or use the average width multiplied by the path length.

For any area calculation, the Square Footage Calculator handles rectangles, circles, triangles, and trapezoids with unit conversions built in.

Comparison: AllTools vs Omni Calculator vs Inch Calculator

All three tools give you the same mathematical result — gravel volume is gravel volume. The difference is user experience. AllTools provides a clean, fast interface without being buried in ads. Omni Calculator and Inch Calculator offer extensive educational content alongside their calculators but load slower due to heavy ad scripts.

FAQ

How do I convert cubic yards to tons?

Multiply cubic yards by the density factor for your gravel type. Crushed stone: multiply by 1.4. Pea gravel: multiply by 1.3. River rock: multiply by 1.35. So 5 cubic yards of crushed stone = 5 x 1.4 = 7 tons. The Gravel Calculator handles this conversion automatically.

How much does a truckload of gravel cost?

A standard dump truck holds 10-14 cubic yards. At $40-85 per cubic yard for common types, a full truck costs $400-1,200 for material plus $50-150 for delivery. A half-truck (5-7 cubic yards) is typically available at the same per-yard rate with the same delivery fee, making it less cost-effective per yard.

Should I use crushed stone or pea gravel for my driveway?

Crushed stone. Its angular edges interlock when compacted, creating a firm, stable surface that resists rutting under vehicle weight. Pea gravel’s round shape means the stones roll against each other — cars create ruts and the surface shifts over time. Crushed stone is the universal choice for driveways among landscape professionals.

How much gravel do I need for a 10x10 patio base?

For a 10x10 foot patio with a 4-inch gravel base: 10 x 10 x 0.333 = 33.3 cubic feet = 1.23 cubic yards. Add 10% for compaction: about 1.35 cubic yards, or roughly 1.9 tons of crushed stone. The Gravel Calculator gives you this answer in seconds.

Does gravel go on top of landscape fabric?

For decorative applications and pathways, yes — lay landscape fabric first, then spread gravel on top. The fabric prevents weed growth through the gravel while allowing water drainage. For structural applications like driveway bases, skip the fabric as it can prevent the gravel from bonding with the substrate.

How do I account for slopes?

For sloped areas, gravel depth varies — thicker at the bottom, thinner at the top, or vice versa. Use the average depth across the slope. Measure depth at the shallow end and the deep end, add them together, and divide by two. Use that average depth in your calculation. For steep slopes, add 15-20% extra material to account for settling and migration.

Start Calculating

Open the Gravel Calculator and enter your project dimensions. Get instant results for cubic yards, tons, and estimated cost — no account, no app, no signup.

For related projects: calculate concrete for footings and slabs, estimate mulch for garden beds, figure out square footage for any area, or plan brick layouts for walls and patios. Explore the full Construction tools category. Questions? Visit the FAQ. Want a new tool? Suggest it.