Gravel Calculator: How Many Tons Do You Need? Complete Guide

How to Calculate Gravel in Tons

The basic formula is straightforward: Length (ft) x Width (ft) x Depth (ft) / 27 = cubic yards. Then multiply cubic yards by the gravel density (typically 1.4 tons per cubic yard for most crushed stone) to get tons.

Example: A 20 x 10 foot driveway at 4 inches deep = 20 x 10 x 0.33 / 27 = 2.44 cubic yards = roughly 3.4 tons of gravel.

Always add 10-15% extra for waste, compaction, and uneven surfaces. It is far cheaper to have a small amount left over than to order a second delivery, which typically costs $50-$150 in additional delivery fees.

Use our free Gravel Calculator at BuildCalc Pro to skip the math. Enter your dimensions and depth, select your gravel type, and get an instant tonnage and cost estimate.

Gravel Coverage Rates by Depth

1 ton of gravel covers approximately: 100 square feet at 2 inches deep, 80 square feet at 3 inches deep, 60 square feet at 4 inches deep, or 50 square feet at 5 inches deep. These figures are for standard crushed stone with a density of 1.4 tons per cubic yard.

Recommended depths by project: Driveways need 4-6 inches total (2-3 inch base layer plus 2-3 inch top layer). Walkways and garden paths need 2-3 inches. French drain backfill needs 6-12 inches. Patio bases need 4-6 inches of compacted gravel.

Pea gravel and decorative stone are slightly lighter (1.2-1.3 tons per cubic yard) so you will need slightly less by weight. River rock is heavier (1.5-1.6 tons per cubic yard) so adjust accordingly.

Gravel Costs: What to Budget

Crushed stone and gravel base: $20-$35 per ton delivered. This is the most common and affordable option for driveways, bases, and drainage.

Pea gravel: $25-$50 per ton delivered. Popular for walkways, patios, and decorative areas. The smooth, rounded stones are comfortable underfoot.

Decomposed granite: $30-$50 per ton. Compacts well for walkways and patios. Creates a natural, earth-toned surface.

Decorative stone and river rock: $50-$150 per ton depending on colour and source. Used for landscaping accents, garden beds, and water features.

Delivery fees: Most quarries charge $50-$150 per delivery within 20 miles. Minimum orders are typically 1-2 tons. Ordering closer to the minimum increases your per-ton cost significantly when you factor in delivery.

Pro tip: Ordering by the truckload (10-20 tons) is significantly cheaper per ton than buying bags from a home improvement store. A 0.5 cubic foot bag at $5 equals roughly $270 per ton versus $25-$35 per ton delivered in bulk.

Choosing the Right Gravel Type

Driveways: Use a 3-layer system for best results. Bottom layer: 4-inch minus crushed rock for stability. Middle layer: #57 stone (3/4 inch) for drainage. Top layer: #8 or #411 stone (3/8 inch) or crusher run for a smooth driving surface.

Walkways and paths: Pea gravel or decomposed granite are the most comfortable options. Install edging to keep the gravel contained. A depth of 2-3 inches is sufficient.

Drainage projects: Clean #57 stone (no fines) is the standard for French drains and drainage trenches. The uniform size allows maximum water flow. Wrap the stone in landscape fabric to prevent soil infiltration.

Garden beds and landscaping: Decorative stone or river rock in 1-3 inch sizes. Choose colours that complement your home exterior. A 2-3 inch layer effectively suppresses weeds when installed over landscape fabric.

Under concrete and pavers: Use compactable gravel base (crusher run or 3/4 inch minus). This material contains both stone and fine particles that lock together when compacted, creating a stable base.

Common Gravel Ordering Mistakes

Underestimating depth: A 2-inch layer of gravel on a driveway will not hold up to vehicle traffic. You need 4-6 inches minimum for driveways, which is 2-3x more material than many people initially budget.

Forgetting about compaction: Loose gravel compacts by roughly 30% when driven on or tamped. If you need 4 inches of finished depth, start with 5-6 inches of loose material.

Wrong gravel type: Round pea gravel shifts under vehicle tires and is a poor choice for driveways. Angular crushed stone locks together and creates a stable surface. Save the round stuff for walkways and decorative areas.

Ignoring the base: Putting nice gravel directly on bare soil leads to sinking and mud mixing. Install landscape fabric first, then the gravel, for a clean long-lasting installation.

Use our free Gravel Calculator at buildcalcpro.org to get your exact tonnage, avoid these mistakes, and stay on budget.