How Much Gravel Do I Need? Calculator and Complete Buying Guide

The Quick Formula

Here's the formula for figuring out how much gravel you need:

Length (ft) x Width (ft) x Depth (in) / 12 = Cubic Feet

Then convert to the unit your supplier uses:

• Cubic yards: Cubic Feet / 27
• Tons: Cubic Yards x Material Density (usually 1.35 to 1.5)
• Bags (0.5 cu ft): Cubic Feet / 0.5

Worked Example: Walkway

You're building a walkway that's 30 feet long, 4 feet wide, and you want 2 inches of pea gravel.

1. Area: 30 x 4 = 120 square feet
2. Volume: 120 x 2 / 12 = 20 cubic feet
3. Cubic yards: 20 / 27 = 0.74 cubic yards
4. Tons: 0.74 x 1.35 = 1.0 ton of pea gravel
5. Bags: 20 / 0.5 = 40 bags

So you'd need about 0.74 cubic yards (1 ton) or 40 half-cubic-foot bags.

Worked Example: Driveway

A single-car driveway is typically about 12 feet wide and 40 feet long. At 4 inches of depth:

1. Area: 40 x 12 = 480 square feet
2. Volume: 480 x 4 / 12 = 160 cubic feet
3. Cubic yards: 160 / 27 = 5.93 cubic yards
4. Tons: 5.93 x 1.4 = 8.3 tons of crushed stone

That's a big project — definitely one for bulk delivery, not bags.

Gravel Depth Guide

How deep you go depends entirely on what you're using the gravel for. Too thin and it won't hold up. Too thick and you're wasting money. Here's what works:

Tons vs. Cubic Yards — Understanding Gravel Measurements

This is one of the most confusing parts of buying gravel. Some suppliers sell by the cubic yard. Others sell by the ton. Some quote both. Here's how they relate:

A cubic yard is a volume measurement — a cube 3 feet on each side (27 cubic feet). This is the standard for loose materials like mulch and gravel.

A ton is a weight measurement — 2,000 pounds. Since gravel is heavy, suppliers who weigh their trucks often sell by the ton.

The conversion between them depends on how dense the gravel is:

Types of Gravel and When to Use Each

Crushed Stone

Angular, irregular pieces made by mechanically crushing larger rocks. The jagged edges lock together when compacted, creating a stable, firm surface. This is the workhorse of gravel — used for driveways, road base, drainage, and foundations. Comes in numbered sizes: #57 (3/4 inch, the most common), #3 (1.5 to 2 inches for base layers), and #8 (3/8 inch for top dressing).

• Cost: $25 to $50 per ton
• Best for: Driveways, parking areas, structural base, drainage
• Pros: Locks together, very stable, compacts well
• Cons: Rough on bare feet, not the prettiest option

Pea Gravel

Small, smooth, rounded stones about 3/8 inch in diameter. Named because the stones are pea-sized. Comfortable to walk on, pleasant to look at, and available in natural colors (tan, brown, white, gray). The smooth surface means it shifts easily underfoot, so it needs edging to stay in place.

• Cost: $30 to $55 per ton
• Best for: Walkways, patios, play areas, between pavers
• Pros: Comfortable, attractive, good drainage
• Cons: Shifts and migrates, needs edging, hard to shovel in winter

River Rock

Larger smooth stones, usually 1 to 3 inches, naturally polished by water. Purely decorative — too large and smooth for walking surfaces or driveways. Looks great in dry creek beds, garden borders, and as ground cover in xeriscaping. Very heavy per cubic yard.

• Cost: $45 to $80 per ton
• Best for: Decorative landscaping, dry creek beds, drainage swales
• Pros: Beautiful natural look, virtually no maintenance, doesn't decompose
• Cons: Expensive, very heavy, not walkable as a surface

Decomposed Granite (DG)

Granite that has weathered into a sand-like material with small stone fragments. When compacted (especially with a stabilizer), DG creates a firm, natural-looking surface that works great for paths, patios, and rustic driveways. Popular in the Southwest and Mediterranean-style landscapes.

• Cost: $25 to $50 per ton
• Best for: Pathways, patios, rustic driveways, xeriscaping
• Pros: Natural appearance, compacts into a smooth surface, good drainage
• Cons: Can get muddy when wet, tracks into the house, needs periodic re-compacting

Gravel for Driveways — Complete Guide

A gravel driveway is one of the most cost-effective driveway options, typically costing one-third to one-half the price of asphalt and a fraction of the cost of concrete. But a good gravel driveway isn't just a pile of rocks — it's a layered system.

The Three-Layer System

Professional gravel driveways use three layers:

1. Bottom layer (4 inches): Large crushed stone, #3 or #4 size (1.5 to 2.5 inches). This provides the structural foundation and drainage. Compact this layer before adding the next.
2. Middle layer (2 to 3 inches): Medium crushed stone, #57 size (3/4 to 1 inch). This fills the gaps in the bottom layer and creates a more even base. Compact again.
3. Top layer (1 to 2 inches): Fine gravel, #8 or #9 size (3/8 inch). This gives you the smooth driving surface. Some people use pea gravel on top, but crushed stone locks together better.

Total depth: 6 to 9 inches. For a single-car driveway (12 ft x 40 ft), that's about 9 to 13 cubic yards — or roughly 12 to 18 tons of material.

Driveway Cost Estimate

A typical single-car gravel driveway (12 x 40 ft) costs:

• Materials: $350 to $750 (depending on stone type and local prices)
• Delivery: $75 to $200 (may need multiple loads for 10+ tons)
• Equipment rental (plate compactor): $60 to $100/day
• Total DIY cost: $500 to $1,050
• Professional installation: $1,500 to $3,000

Delivery vs. Pickup

Like mulch, gravel can be purchased in bags or bulk. But gravel is much heavier than mulch, which changes the calculation.

Bagged Gravel (Pickup)

• Typical bag size: 0.5 cubic feet (roughly 40 to 50 pounds per bag)
• Cost: $4 to $8 per bag ($215 to $430 per cubic yard equivalent)
• Best for: Very small projects — under 0.5 cubic yards (less than 27 bags)
• Reality check: A single cubic yard of gravel weighs about 2,800 pounds. That's 56 bags at 50 lbs each. Your car or truck can probably handle 10 to 15 bags at a time.

Bulk Delivery

• Minimum order: Usually 1 to 3 cubic yards, depending on the supplier
• Cost: $25 to $60 per ton or $30 to $75 per cubic yard
• Delivery fee: $50 to $200 depending on distance and amount
• Best for: Any project over 0.5 cubic yards

Bottom line: Unless your project is truly small (a couple of bags for filling around stepping stones), bulk delivery is almost always the way to go with gravel. The weight alone makes bagged gravel impractical for anything more than a very small area.

Cost of Gravel by Type

Gravel prices vary significantly by region, season, and how far you are from a quarry. Here are typical 2024/2025 price ranges to help with budgeting:

Site Preparation Before Gravel

Dumping gravel on bare ground is a recipe for problems a year from now. A little prep work makes the difference between a gravel surface that lasts a decade and one that turns into a weedy, muddy mess within a season.

Step-by-Step Preparation

1. Mark and measure your area. Use stakes and string to outline the exact space. Measure twice — ordering extra gravel is expensive, and returning it is even worse.
2. Remove vegetation. Dig out grass, weeds, and any organic material in the area. You want to be down to bare soil. For driveways, remove at least 4 to 6 inches of topsoil.
3. Grade the surface. For driveways and patios, the surface should slope slightly (about 1/4 inch per foot) away from structures for water drainage. Use a level and a long straight board to check.
4. Compact the soil. Use a hand tamper for small areas or rent a plate compactor for large ones. Loose soil under gravel = sinking and shifting later.
5. Install landscape fabric. Lay heavy-duty woven landscape fabric over the entire area. Overlap seams by at least 6 inches. Pin it down with landscape staples every 2 to 3 feet.
6. Install edging. Metal, plastic, or stone edging contains your gravel and keeps it from migrating into the lawn. This is especially important for pea gravel and other smooth stones that shift easily.
7. Spread and compact gravel. Add gravel in layers (especially for driveways). Spread each layer evenly with a rake and compact before adding the next.

For walkways and small decorative areas, you can simplify this — clear the weeds, lay fabric, add edging, and spread gravel. But for driveways and any area that will bear vehicle weight, don't skip the excavation, grading, and compaction steps.

Working on more outdoor projects? Our mulch calculator can help with garden beds, or check out all of our free home project calculators.