Gravel Calculator: How Much Gravel Do I Need?

How much gravel do I need?

Multiply the area by the depth to get the volume, then convert it into the unit your supplier sells. In US units, length times width in feet, times the depth in inches divided by 12, gives cubic feet. Divide by 27 for cubic yards. Multiply the cubic feet by the stone's density, about 100 lb/ft³, and divide by 2,000 for tons. One cubic yard covers 108 square feet at 3 inches deep and weighs roughly 1.4 to 1.7 tons.

For example, a 10 × 20 ft driveway apron finished at 3 inches needs 50 cubic feet. That is 1.85 cubic yards, about 2.6 tons of all-purpose gravel, or 100 half-cubic-foot bags. Add 10 percent for settling and spillage and order about 2 cubic yards.

Depth and density move the answer the most. Doubling the depth doubles the order, and damp or compacted stone weighs 15 to 25 percent more than the same volume dry and loose. Choose the depth from the project guide below and the material closest to what your supplier sells.

How much gravel do I need for a driveway?

Driveways take more stone than any other gravel job because they are both large and deep. Topping up an existing drive takes 2 to 3 inches of fresh stone, while a new driveway is built 8 to 12 inches deep in compacted layers. The table gives cubic yards and tons for common driveway sizes at three depths.

Building a new gravel driveway in layers

A driveway that stays firm is built from the bottom up in three layers, each compacted before the next goes down:

• Base, 4 to 6 in: large #3 stone, about 2 inches across, that spreads the load and lets water drain out of the subgrade.
• Middle, 3 to 4 in: #57 crushed stone, mostly 3/4 inch, that locks into the base.
• Top, 2 to 3 in: crusher run, also sold as road base, dense-grade aggregate, or #411. Its stone dust packs into a hard surface you can drive on.

The New driveway preset in the calculator loads this stack for a 12 × 50 ft drive: 3 in of crusher run over 4 in of #57 over 5 in of #3 base stone. That comes to 22.2 cubic yards and about 30.8 tons. Crown the finished surface about 1/4 to 1/2 inch per foot so rain runs off to the edges.

How much does a yard of gravel weigh?

A cubic yard of gravel weighs about 2,800 to 3,400 pounds, or 1.4 to 1.7 US tons, as it usually comes off a supplier's scale. Dry, loose stone is lighter: all-purpose gravel is about 2,835 pounds per cubic yard, 3/4 inch crushed stone about 2,700, pea gravel about 2,600, and river rock about 2,400. Crusher run is among the heaviest at about 2,970 pounds, because its stone dust fills the gaps between the stones.

The table lists approximate dry, loose weights for every material in the calculator, plus what a standard 0.5 cubic foot bag of each one weighs.

Wet stone runs 15 to 20 percent heavier, and material compacted in place is denser still. When your supplier gives a weight per yard for their product, choose Custom density in the calculator and use their figure.

Gravel tons to cubic yards (and yards to tons)

Quarries usually sell by the ton and landscape yards by the cubic yard, and you need the stone's weight per yard to switch between them. One ton of all-purpose gravel is about 0.7 cubic yards, and one cubic yard is about 1.42 tons. Use the converter for your material, or read common amounts from the tables.

Tons are US short tons of 2,000 lb. Dry columns use all-purpose gravel at 105 lb/ft³ (1.42 tons per cubic yard); damp columns use 1.7 tons per cubic yard, the top of the usual delivered range.

How much does a yard of gravel cover?

One cubic yard of gravel covers 108 square feet at 3 inches deep, 162 square feet at 2 inches, and 81 square feet at 4 inches. The shortcut is 324 divided by the depth in inches. By weight, a ton of all-purpose gravel covers about 76 square feet at 3 inches.

Coverage assumes a level, prepared surface. Soft or uneven ground swallows more stone, so round up.

How much pea gravel do I need?

Pea gravel is small rounded stone about 3/8 inch across, and it is lighter than crushed stone: about 96 lb/ft³, or roughly 2,600 pounds (1.3 tons) per cubic yard. A 0.5 cubic foot bag weighs about 48 pounds.

Lay it 2 inches deep on paths and 3 inches deep on patios and seating areas, over landscape fabric and inside firm edging so it does not wander. A 12 × 12 ft pea gravel patio at 3 inches takes 36 cubic feet: 1.33 cubic yards, about 1.7 tons, or 72 bags. Round stones roll underfoot, so a compacted crushed stone base or a gravel stabilizer grid underneath keeps a patio firmer.

Play areas are a safety question rather than a coverage one. The U.S. Consumer Product Safety Commission's Public Playground Safety Handbook sets minimum loose-fill depths by fall height, typically 9 inches or more, so size those beds from its table.

How to calculate gravel by hand

The calculator does the unit conversions, but the method is short enough to check on paper. That helps when a supplier quotes in different units than you measured in.

1. Measure the area: length × width for rectangles, or π × radius² for circles. Split irregular shapes into rectangles and add them up.
2. Choose the finished depth from the project guide below, in inches.
3. Convert the depth to feet by dividing the inches by 12.
4. Multiply the area in square feet by the depth in feet to get cubic feet, then divide by 27 for cubic yards.
5. Multiply the cubic feet by the material density in lb/ft³ to get pounds, then divide by 2,000 for US tons.
6. Multiply the volume or the weight by your supplier's unit price, and add 5 to 10 percent for settling, spillage, and an uneven subgrade.

Worked example: a 10 × 20 ft driveway apron

Here is the full calculation for a single-car driveway apron, 10 ft wide by 20 ft long, finished at 3 inches of all-purpose gravel at 105 lb/ft³.

1. Area: 10 ft × 20 ft = 200 square feet.
2. Depth in feet: 3 in ÷ 12 = 0.25 ft.
3. Volume: 200 sq ft × 0.25 ft = 50 cubic feet.
4. Cubic yards: 50 ÷ 27 = 1.85 cubic yards.
5. Weight: 50 cubic feet × 105 lb/ft³ = 5,250 pounds, or 2.63 tons.
6. Bags: 50 cubic feet ÷ 0.5 cu ft per bag = 100 bags.
7. Cost: 1.85 cubic yards × $45 per cubic yard = about $83 of material, plus a typical $50 to $150 delivery charge.

With 10 percent extra for compaction and spillage the order becomes 2.04 cubic yards, or about 2.9 tons. Most yards sell in half-yard steps, so you would order 2 to 2.5 cubic yards. The same job in bags would cost $400 to $800, which is why anything above about half a cubic yard is worth buying in bulk.

Recommended gravel depth by project

Depth drives the total more than any other input, and the right depth depends on load, drainage, and whether the stone is structural or decorative. These are the depths most contractors build to.

These are finished, compacted depths. Crushed stone loses roughly 15 to 20 percent of its loose depth when it is compacted, so order that much more than the finished volume if the surface has to meet grade after rolling.

Choosing gravel for the job

Gravel is sold by size and shape. Angular crushed stone locks together and holds a grade, while rounded pea gravel and river rock stay loose. Size numbers such as #3, #57, and #8 come from the ASTM D448 and AASHTO M 43 gradation standards, so they describe much the same stone at any quarry. Trade names such as crusher run, road base, and 2A modified vary by region, so ask for the gradation if you are unsure.

• Driveways and parking areas: Angular stone in compacted layers. A new drive needs 8 to 12 inches in total; a resurfacing job needs 2 to 3 inches of fresh stone raked into the existing surface.
• Garden paths and decorative beds: Pea gravel, river rock, or decomposed granite at 2 to 3 inches over landscape fabric. Deeper than 3 inches is wasted stone that traps leaves and is hard to walk on.
• Drainage and French drains: Washed #57 stone with no fines keeps the voids open so water can reach the pipe. A typical drain uses a 2 inch bed under the pipe and 4 to 6 inches of cover over it.
• Bases for pavers, sheds, and slabs: 4 to 6 inches of compacted crushed stone or crusher run gives a stable, free-draining foundation. Extend the base past the finished edge so the perimeter does not slump.

Practical tips for ordering gravel

• Order 5 to 10 percent more than the calculated volume for settling, spillage, and uneven subgrade, and closer to 20 percent if the stone will be mechanically compacted.
• Check whether a quote is per cubic yard or per ton before comparing suppliers. At 1.4 tons per yard, $40 per ton and $56 per yard are the same price.
• Ask for washed clean stone for drainage and for graded crusher run where the surface has to compact. The two are not interchangeable even at the same nominal size.
• Lay landscape fabric under decorative gravel so the stone does not sink into the soil and weeds do not push through.
• Compact driveway stone in 2 to 3 inch lifts with a plate compactor rather than in one deep pass, or the lower material never locks together.
• Confirm delivery access and the minimum order. Many yards charge $50 to $150 per load and will not deliver less than a full yard, so small jobs cost more per yard than the headline price.

Related calculators

Groundwork usually needs a grade as well as a quantity. These three cover the slope side of the same jobs.

• Slope calculator

  Grade a driveway or gravel pad so water sheds off it: percent grade, ratio, and fall per foot from rise and run.

• Pipe slope calculator

  A French drain only works if the pipe falls. Check the minimum slope for the pipe diameter you are bedding in the stone.

• Ramp slope calculator

  If a gravel path is part of an accessible route, check its running slope against the 1:12 ADA maximum.

Gravel calculator FAQ

The questions people ask most before they order stone, answered with numbers.

How this calculator works

Volume is area × depth, and weight is volume × bulk density. Each material uses an approximate dry, loose bulk density, for example 105 lb/ft³ for all-purpose gravel and 96 lb/ft³ for pea gravel. Bulk density is the property ASTM C29 measures for aggregates, and these figures sit inside the conversion factors suppliers commonly publish, about 1.2 to 1.7 tons per cubic yard.

Tons are US short tons of 2,000 lb, metric tonnes are 1,000 kg, and a cubic yard is 27 cubic feet or 0.765 cubic meters. Bag counts assume 0.5 cu ft bags in US units and 20 kg bags in metric. Layered builds are summed layer by layer with each stone's own density, and the extra allowance multiplies the whole order.

The results are planning estimates. Confirm the product density and the price unit with your supplier before you order.

Last reviewed September 28, 2026.