Gravel Calculator

How to Use This Gravel Calculator

This gravel calculator estimates the cubic yards, tons, and cost of gravel needed for any coverage area. Enter the length and width of your project area and the depth of gravel you need. Select your material type — standard gravel, pea gravel, or gravel with sand — and the calculator pre-fills the density value, which you can override. Add an optional price per ton or per cubic yard to get an instant cost estimate.

How to Calculate Cubic Yards of Gravel

Calculating gravel starts with one formula:

Cubic yards = (Length ft × Width ft × Depth ft) ÷ 27

Convert depth from inches to feet before calculating (divide inches by 12). To get weight in tons, multiply cubic yards by the material density in tons per cubic yard.

Step-by-Step Example

1. Measure your driveway: 50 ft long × 12 ft wide
2. Choose a depth: 4 inches = 0.333 ft
3. Volume: 50 × 12 × 0.333 ÷ 27 = 7.41 cubic yards
4. Weight: 7.41 × 1.42 = 10.52 tons (at 105 lbs/ft³)
5. At $45/ton: $473 in materials

Gravel Driveway Coverage Guide

Here are common project sizes with pre-calculated volumes and weights at 4-inch depth:

• 10×20 ft parking pad (4 in) — 2.47 yd³ · 3.50 tons
• 12×50 ft driveway (4 in) — 7.41 yd³ · 10.52 tons
• 12×100 ft long driveway (4 in) — 14.81 yd³ · 21.04 tons
• 20×20 ft patio (3 in) — 3.70 yd³ · 5.26 tons
• 50×50 ft yard area (2 in) — 15.43 yd³ · 21.91 tons

For a concrete driveway comparison, concrete typically costs more upfront but requires less maintenance than gravel. Gravel driveways are ideal for rural properties and long runs where concrete would be prohibitively expensive.

Types of Gravel and Their Uses

• Standard gravel (0.5–2 in) — Best for driveways and drainage. Angular edges lock together and resist movement under vehicle traffic.
• Pea gravel — Smooth and rounded, ideal for walkways, playgrounds, and around plants. Shifts more easily, so not the best for driveways.
• Gravel with sand — A blended mix that compacts well. Good for base layers and around drainage pipes.
• Crushed stone / limestone — Mechanically crushed, very angular, excellent for driveways and road base. Compacts into a hard surface.
• River rock — Smooth decorative stones. Used for landscaping, water features, and garden borders.

Gravel Cost Estimates

• Bulk gravel: $40–$55 per ton delivered · $30–$40 per cubic yard
• Pea gravel: $35–$50 per ton · slightly less than standard gravel
• Crushed stone: $45–$65 per ton delivered
• Installation (spreading + grading): $0.75–$2.50 per sq ft additional

Prices vary significantly by region and delivery distance. Always get at least two quotes and confirm whether the price includes delivery. Explore our full set of construction calculators for related project estimates.

Gravel Drainage Properties and Why They Matter

One of gravel's most valuable properties is its drainage. Unlike soil or clay, properly sized gravel allows water to pass through while supporting the weight above it. This makes gravel essential in applications where drainage is critical:

• French drains — a perforated pipe surrounded by 6–12 inches of washed gravel (typically #57 stone) redirects groundwater away from foundations. The gravel prevents soil from clogging the pipe.
• Driveway base — a gravel driveway drains rainwater immediately rather than pooling. Properly graded gravel driveways shed water to the sides, preventing erosion and pothole formation.
• Around foundations — 6–12 inches of gravel along a foundation directs surface runoff away and prevents water from pooling against the basement wall. Often combined with a perforated drain tile.
• Under concrete slabs — a 4-inch compacted gravel base under concrete driveways, patios, and slabs prevents frost heave and provides a stable, well-drained surface for the concrete to bear on.

For maximum drainage, use angular, uniformly sized stone (#57 or #67 crushed stone) rather than gravel with sand fines. Sand-laden mixes reduce permeability. For patio and path installations, consider pavers over a gravel base — our paver calculator can size those materials.

Decomposed Granite and River Rock: Specialty Gravel Types

Beyond standard crushed stone, several specialty gravel types are popular for landscaping and hardscaping:

• Decomposed granite (DG) — fine-textured granite particles that compact to a firm, natural-looking surface. Popular for garden paths, xeriscaping, and low-water landscapes in the West. Available natural, stabilized (with polymer binder), or dyed. Stabilized DG holds its shape well; natural DG can be muddy when wet.
• River rock — smooth, rounded stones 1–5 inches in diameter, tumbled naturally by water. Used for decorative beds, water features, and dry creek beds. Does not compact well and shifts under foot traffic. Density is similar to standard gravel at 100–105 lbs/ft³.
• Lava rock — lightweight, porous, reddish-brown volcanic rock. Popular for ornamental beds and fire pits. Very light (only 50–70 lbs/ft³) compared to standard gravel, so a given volume weighs much less. Provides good drainage but can blow away in high wind.