Gravel Calculator

What is a Gravel Calculator?

Gravel and crushed stone are the unsung heroes of nearly every outdoor construction project, providing crucial drainage, stable subbases, and beautiful decorative finishes. However, calculating the exact volume of irregular aggregate you need is notoriously challenging. Because gravel compacts differently based on stone size and grading, a simple length-by-width calculation often leaves you severely short or drowning in excess material.

A gravel calculator takes the guesswork out of ordering bulk aggregates. Whether you are laying a 6-inch crushed stone base for a new driveway, filling a French drain, or spreading decorative pea gravel across a landscape bed, this tool precisely converts your exact dimensions and depth into required cubic yards, cubic feet, and delivery tonnage. By factoring in specific gravel densities and compaction wastage, it ensures you order the exact amount needed to achieve a stable, long-lasting surface.

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How to Use the Gravel Calculator - Cubic Yards, Tons & Driveway Gravel

1. Choose the project shape

Select rectangle, circle, or irregular area shape to match your driveway, pathway, bed, or drainage trench footprint.

2. Enter dimensions and depth

Input length and width in feet and depth in inches. Depth has a large effect on total tonnage, so measure or plan carefully before entering.

3. Select the gravel type

Different gravel types have different densities. Pea gravel, crushed stone, and river rock all have slightly different weights per cubic yard.

4. Review tons and cubic yards together

Suppliers quote in both units. Use cubic yards for volume ordering and tons for weight-based delivery tickets. Both outputs are shown so you can match whichever unit your supplier uses.

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Key Formulas

Volume formula

Cubic Yards = Length(ft) × Width(ft) × Depth(in) ÷ 12 ÷ 27

Converts project dimensions into cubic yards, the standard volume unit for bulk gravel ordering.

Weight formula

Tons = Cubic Yards × Gravel Density(tons/yd³)

Converts cubic yards to tons using the gravel type density. Crushed stone is typically 1.4–1.5 t/yd³; pea gravel around 1.2–1.35 t/yd³.

Coverage formula

Coverage(sq ft) = (Cubic Yards × 27) ÷ (Depth(in) ÷ 12)

Calculates how many square feet a given volume of gravel will cover at a specified depth. Useful for checking whether a quoted quantity matches your area.

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Key Factors

Consideration

Gravel type and density

Pea gravel, crushed limestone, granite, and recycled concrete all have different densities and structural properties. Choose based on intended use, not just cost.

Consideration

Soil conditions

Soft, clay, or waterlogged soils may need deeper gravel layers or geotextile fabric to prevent stone sinking into the ground over time.

Consideration

Compaction

Crushed angular stone compacts when driven or rolled, which can reduce the surface layer depth. Factor in compaction loss when planning driveway gravel depths.

Consideration

Wastage and spreading

A 10% wastage allowance is standard. Driveways with curved edges, sloped areas, or spreading from vehicles may need more.

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Gravel Depth Guide

Decorative pathway or bed

2–3 inches

Shallow layer for visual coverage in garden beds, pathways, and decorative borders where load bearing is not required.

Residential driveway

4–6 inches

Standard depth for a stable gravel driveway. Soft or clay soils may need a deeper layer or a geotextile fabric underneath.

Drainage layer

6–12 inches

French drains and soak-away systems often require deeper gravel beds to handle water flow rates and prevent silting.

Structural subbase

Engineer specified

Subbases under concrete slabs, foundations, and paving are specified by engineers based on soil conditions and load requirements.

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Typical Project Ranges

Garden path or small bed

0.5–2 cubic yards

Often manageable with bags or a small bulk delivery. Bagged decorative gravel is convenient for tight garden spaces.

Medium driveway or drainage

3–8 cubic yards

Bulk delivery is usually more economical. Many suppliers have minimums in this range, so confirm with your local supplier.

Large driveway or subbase

10+ cubic yards

Multiple truckloads may be needed. Confirm access for delivery trucks and plan where to stage material before it is spread.

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Related Planning Tools

Concrete Calculator

Estimate concrete cubic yards and bag counts for slabs, footings, and columns poured on a gravel subbase.

Sand Calculator

Calculate sand volume, weight, and bags for bedding layers, paver bases, and landscaping projects.

Asphalt Calculator

Estimate asphalt tonnage and truckloads for driveways and paving projects built over a gravel base.

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Frequently Asked Questions

How do I calculate how much gravel I need?

Multiply the length by width to get area in square feet, then multiply by the depth in feet and divide by 27 for cubic yards. This gravel calculator handles the conversion automatically for rectangles, circles, and irregular shapes.

How many cubic yards of gravel do I need for a driveway?

A typical single-car driveway at 10 feet wide, 40 feet long, and 4 inches deep needs about 4.9 cubic yards of gravel. Adding 10% wastage brings it to roughly 5.4 cubic yards.

How many tons is one cubic yard of gravel?

One cubic yard of gravel typically weighs about 1.3 to 1.5 tons depending on the type. Pea gravel is lighter than dense-graded crushed stone, which can weigh closer to 1.5 tons per yard.

How deep should gravel be for a driveway?

Most residential driveways use 4 to 6 inches of gravel in a single layer. Heavily used driveways or soft soil conditions may need a deeper base or a two-layer approach with larger stone below and finer gravel on top.

What is the difference between pea gravel and crushed stone?

Pea gravel is smooth and rounded, commonly used for pathways, drainage, and decorative beds. Crushed stone has angular edges that lock together better, making it more suitable for driveways, subbases, and structural fill.

How much area does one ton of gravel cover?

One ton of gravel covers approximately 80 to 100 square feet at 2 inches deep. At 4 inches deep, one ton covers around 40 to 50 square feet. Coverage changes with gravel type and compaction.

Should I add extra gravel for wastage?

Yes. A 10% wastage allowance is standard for most gravel projects. Driveways with curved edges or sloped sites may need a higher allowance to account for spreading losses and uneven ground.

What size gravel is best for a driveway?

A common approach is to use 2 to 3 inch base rock at the bottom, followed by a middle layer of #57 stone, and a top layer of fine crushed stone or gravel around 3/8 inch for a stable driving surface.

Can I use this calculator for pea gravel?

Yes. Select the pea gravel option and enter your project dimensions. The calculator adjusts the weight estimate to match the lower density of pea gravel compared to crushed stone.

How do I convert cubic yards to tons for gravel?

Multiply cubic yards by the gravel weight in tons per yard. Crushed stone is typically 1.4 to 1.5 tons per cubic yard. The calculator handles this conversion automatically once you select the gravel type.

Disclaimer

This calculator provides planning estimates only. Actual gravel quantities depend on site conditions, compaction, soil type, and supplier delivery weights. Confirm final quantities with your supplier before ordering.

Calculate Cubic Yards, Tons and Coverage