Gravel Calculator — How Much Gravel Do I Need?

How to Use This Gravel Calculator

Whether you're paving a driveway, filling a fire pit base, or laying a french drain, getting your gravel estimate right on the first call saves you an extra delivery charge and the hassle of a short load. Here's exactly how to use it:

1. Choose your shape tab. Rectangular Area handles driveways, patios, and garden paths. Circular Area is for round fire pit bases and circular accent areas. Custom Area is for when you already have square footage from a landscape plan. French Drain / Trench handles drainage projects where depth is the dominant dimension.
2. Enter your dimensions. Measure length and width in feet. For a driveway, measure the full length and average width. For irregular areas, break them into rectangles and use the "Number of Areas" multiplier, or use the Custom Area tab and enter total square footage.
3. Set your depth. Click a preset (2" for decorative, 3" for walkways, 4" for driveways — the recommended default, 6" for heavy traffic or base layers) or type a custom value. Depth is the biggest variable — getting this right prevents short loads.
4. Select your gravel type. Each type has a different density (lbs per cubic yard), which changes your tonnage. Lava rock is nearly three times lighter than decomposed granite. The volume math is identical — only weight and cost-per-ton differ.
5. Enter your prices. Default is $50/ton and $65/yd³ — reasonable national averages. Get a quote from your local quarry or landscape supply yard for accuracy. Prices vary by 30–50% by region and supplier.
6. Click Calculate. You'll see tons needed (the primary unit gravel is sold in), cubic yards, cubic feet, weight in pounds, estimated cost, and a side-by-side bulk vs. bags comparison.

Worked example: A driveway that is 50 ft long × 12 ft wide at 4 inches deep. Volume = (50 × 12 × 4/12) ÷ 27 = (600 × 0.333) ÷ 27 = 200 ÷ 27 = 7.41 cubic yards. Using Crushed Stone #57 (2,700 lbs/yd³): Tons = 7.41 × 2,700 ÷ 2,000 = 10.0 tons. At $50/ton, that's approximately $500.

If you're also laying a concrete edging or apron around the driveway, check our Concrete Calculator. For adjacent garden beds, see the Mulch Calculator.

Gravel Calculation Formulas

All gravel calculations are volume-first, then converted to weight using the density of your gravel type. Here are the formulas used:

Rectangular Area (driveways, patios, paths)

Example: 10 ft × 10 ft at 4 inches deep, Crushed Stone #57 (2,700 lbs/yd³)

Circular Area (fire pit bases, round accents)

French Drain / Trench

Why 27?

There are 27 cubic feet in one cubic yard (3 × 3 × 3 = 27). Bulk gravel and crushed stone are sold by the cubic yard or ton in the US. One cubic yard of crushed stone weighs approximately 1.35 tons (2,700 lbs); one cubic yard of lava rock weighs just 0.55 tons (1,100 lbs).

Gravel Type Densities

ℹ️ Densities are approximate. Moisture content, compaction, and exact stone size all affect real-world weight slightly.

Gravel Buying Guide

Bulk vs. Bagged Gravel

The decision between bulk and bagged gravel comes down to project size and access:

• Bulk gravel (loose, by the ton or cubic yard) is the right choice for anything over half a ton. Prices range from $25–$75/ton depending on type and delivery distance. Bulk is delivered by dump truck — you need to designate a drop zone on your driveway or in the work area. Minimum delivery is usually 1–3 tons.
• Bagged gravel (0.5 cu ft or 50 lb bags from home improvement stores) costs significantly more per ton — typically $4–$8 per 50 lb bag, equivalent to $160–$320/ton. But bags are manageable without equipment, require no minimum order, and can reach backyard projects inaccessible to a dump truck.

Break-even point: At most projects over half a ton (about 15–20 bags), bulk delivery is cheaper even after delivery fees. The calculator shows you the exact comparison for your project size.

Gravel Types and Best Uses

• Pea Gravel — Small, smooth, rounded stones (3/8" average). Comfortable underfoot for bare feet. Great for playgrounds, patio infill, and decorative paths. Shifts underfoot so it's not ideal for high-traffic driveways without edging. Price: $35–$55/ton.
• Crushed Stone #57 — Angular, 3/4" crushed limestone or granite. The standard driveway gravel. Interlocks when compacted, provides good drainage, and is widely available. Excellent as a base layer under concrete or pavers. Price: $30–$50/ton.
• Crusher Run — Mixed crushed stone and stone dust that compacts into a firm surface. Also called "road base" or "compacted gravel." The best gravel for driveways that need to carry heavy vehicles. Must be compacted with a plate compactor. Price: $25–$45/ton.
• River Rock — Smooth, rounded stones in larger sizes (1"–3"). Used for erosion control, creek beds, and decorative landscaping. More expensive than crushed stone. Doesn't compact well — not suitable for driveways. Price: $50–$100/ton.
• Decomposed Granite — Fine, gritty material that packs into a stable surface. Used for xeriscaping, walkways, and dry creek beds in arid climates. Heavy (3,000 lbs/yd³). Can be stabilized with a polymer binder for a firmer path. Price: $40–$70/ton.
• Marble Chips — White to off-white decorative stone. Used in formal garden beds and around ornamental plantings. More expensive than plain crushed stone. Price: $100–$200/ton.
• Lava Rock — Porous, lightweight volcanic rock. The lightest option at 1,100 lbs/yd³ — about 40% the weight of crushed stone. Used in decorative beds, fire pit surrounds, and as a drainage medium. Does not pack. Price: $80–$150/ton.

Regional Price Ranges (2026)

• Northeast (NY, MA, CT): $45–$75/ton delivered
• Southeast (FL, GA, NC): $30–$55/ton delivered
• Midwest (OH, IL, MN): $32–$55/ton delivered
• South-Central (TX, OK): $28–$50/ton delivered
• West Coast (CA, WA, OR): $50–$85/ton delivered

Quarry pickup runs $8–$20/ton cheaper than delivered pricing. Minimum delivery loads are typically 1–3 tons; expect a $50–$100 small-load fee for deliveries under 5 tons.

How Deep Should Gravel Be?

Depth is the most important variable in a gravel project — it determines both the amount you need and the performance of the surface:

• Decorative beds and borders: 2 inches. A 2-inch layer of pea gravel or river rock provides full coverage and a clean look. For purely decorative applications, there's no need to go deeper. Less gravel also means less weed suppression — add landscape fabric underneath if weeds are a concern.
• Walkways and garden paths: 3 inches. Three inches provides a stable walking surface that resists displacement. For comfort, use rounded pea gravel; for stability, use angular crushed stone. Lay on a 1-inch sand base over compacted soil.
• Standard driveways: 4 inches. The minimum for a residential driveway that handles standard passenger vehicles. For best results, use a 4-inch layer of Crusher Run or Crushed Stone #57 compacted with a plate compactor. Add a 1-inch top dressing of finer gravel if a smoother surface is desired.
• Heavy-traffic driveways and parking areas: 6 inches. For pickup trucks, RVs, and regular heavy loads, a 6-inch compacted base is the minimum. Many contractors recommend a two-layer system: 4 inches of Crusher Run base compacted first, then 2 inches of #57 stone on top.
• French drains: 12–24 inches total depth. The gravel in a french drain fills the trench around the perforated pipe. Typical residential french drains are 12–18 inches deep; more severe drainage problems may require 24 inches or deeper. Use #57 or washed stone, never pea gravel, which migrates into the pipe.
• Base layer under concrete or pavers: 4–6 inches. Gravel provides drainage and stability under concrete slabs and pavers. Use clean crushed stone #57 or limestone; compact thoroughly. Skipping or underbuilding the base is the #1 cause of cracked or heaved concrete in freeze-thaw climates.

Frequently Asked Questions