Gravel Calculator

Cubic yards and tons of gravel for driveways, walkways, and pads. Updated for 2026.

Last reviewed July 2026 · Free · Nothing you enter is stored

How this calculator works

Cubic yards = square footage × depth in inches ÷ 324. Tonnage uses the standard conversion of 1.4 tons per cubic yard for common crushed stone and pea gravel (denser materials like DG run slightly higher). Cost uses the national average of about $40 per cubic yard for material, with a typical range of $15–$75 depending on stone type.

The waste allowance

This calculator works out the volume of the finished, compacted layer you want on the ground. Loose gravel is not the same thing. Aggregate delivered from a quarry arrives full of voids, and once it is spread and rolled those voids close up, so the material shrinks into place. The common trade allowance is to order roughly 20 to 25 percent more loose material than the compacted volume you calculated. Treat that as a rule of thumb rather than a specification: it is a figure the trade uses, not one published by a quarry or an aggregate standard, and the true shrinkage depends on the gradation of the stone, how wet it is and how hard you compact it. The second reason to round up is that suppliers sell in whole yards or whole tons, and half a yard short across a driveway means a thin patch you will notice for years.

Yards, tons, and the conversion nobody can pin down

Volume is the easy part. Square footage multiplied by depth in inches and divided by 324 gives cubic yards, and that arithmetic is exact. The trouble starts when the supplier quotes by the ton, because converting yards to tons requires a density figure, and there is no single correct one.

Crushed stone generally falls somewhere around 1.4 to 1.7 tons per cubic yard. That is a working range rather than a standard. No quarry publishes a universal figure and no ASTM specification establishes one, because density changes with the parent rock, the gradation, the amount of fines in the mix and how much water the pile has absorbed since the last rain. A yard of the same product can weigh noticeably more in March than in August.

For pea gravel and river rock the situation is worse: we could not verify a defensible density figure for either. If your supplier sells those by weight, ask them what their material actually runs per yard. Any yard has that number, because they weigh loads all day, and a two minute phone call is more reliable than any conversion table on the internet, including this one.

Depth, and building a base in lifts

A garden walkway is conventionally built on about four inches of compacted aggregate. A driveway needs four to eight inches, with the deeper end where the subgrade is soft clay, where drainage is poor, or where delivery trucks and heavy vehicles will use it. These are trade conventions rather than code requirements, and a local contractor who knows the soil in your area will give you a better number than any general rule.

The depth matters less than how it is placed. Aggregate compacts properly in lifts of roughly three to four inches at a time. Dump eight inches in one go, run a plate compactor over the surface, and the top two inches lock up while everything underneath stays loose. It looks finished on the day it is laid and then settles into ruts through the first wet season, usually exactly where the tyres run.

This is also why the base is worth more attention than the surface. The decorative layer on top is what you see, but the load is carried by the compacted aggregate beneath it. A driveway that ruts and potholes is almost never failing because the top dressing was too thin.

Choosing the right stone for what you are building

Aggregate broadly divides into graded material, which contains a mix of sizes down to fine dust, and open-graded material, which has been screened to a single size with the fines washed out. They behave in completely opposite ways, and using the wrong one is the most expensive mistake on this page.

Graded aggregate, sold as crusher run, quarry process, or dense grade depending on where you live, compacts and locks. The fines fill the voids between the larger pieces and the whole layer knits into something close to a solid surface. That is what you want under a driveway, a shed pad, a patio or a retaining wall.

Open-graded decorative stone, including washed river rock and most pea gravel, will never lock up. Uniform round pieces with nothing between them simply roll over one another under load. It drains extremely well, which is why it belongs in French drains and around footings, and it looks good as a top dressing over a proper base. Laid several inches deep as a driveway in its own right, it migrates to the edges and leaves you pushing a shovel around every spring.

Ordering and taking delivery

Give the supplier three things: the volume in cubic yards, the product name you actually want, and the depth you are placing it at. If they quote in tons, ask what their density is for that specific product rather than converting it yourself. Quotes that look different are often the same price once you put them on the same units, and quotes that look identical sometimes are not.

Think about where the load goes before the truck arrives. A tandem dump load is several tons in one pile, and every yard of it will be moved again by hand or by machine. Dumping close to the work, on a tarp or a hard surface rather than on lawn, saves more labour than any other decision on delivery day.

Finally, order the material for the whole job at once where you can. Aggregate from a different batch, or from a different quarry, frequently does not match in colour or size, and on a visible surface the join is obvious.

Coverage and approximate tonnage

Coverage is exact arithmetic: a cubic yard is 27 cubic feet, so it covers 324 square feet one inch deep. The tonnage column comes from a rule-of-thumb density range of 1.4 to 1.7 tons per cubic yard for crushed stone, and is a sanity check on a supplier quote rather than a figure to order from. Nothing here includes the compaction allowance.

Coverage is arithmetic from the definition of a cubic yard. The tonnage range is a widely used trade rule of thumb for crushed stone, not a figure established by a quarry publication or an ASTM standard, and densities for pea gravel and river rock could not be verified at all.

What goes wrong on gravel jobs

Ordering by the ton without knowing the density. Tons only become yards through a density figure that varies by product and by how wet the pile is. Ask the supplier what their material weighs rather than using a generic conversion.

Placing the full depth in one go. Aggregate compacts in lifts of three to four inches. A single deep layer packs at the surface only, then settles and ruts within a season.

Using decorative stone as a driveway base. Washed round stone has no fines and never locks up. A graded material such as crusher run is what compacts into a stable base.

Ordering the compacted volume. Loose material shrinks as it is rolled. The usual allowance is 20 to 25 percent extra, which is a trade rule of thumb rather than a measured constant.

Buying in two batches. Stone from a different load or quarry often differs in colour and size. On anything visible, the seam between batches shows.

Frequently asked questions

Why your state changes the price (but not the quantity)

How much gravel you need is physics — it doesn't care where you live. What it costs does. Labor rates, delivery distance, fuel, and local demand move installed prices by roughly 45 points from end to end: Arkansas, Mississippi, North Carolina sit near the bottom of the range, while Alaska, Hawaii, New York sit at the top. The Price this for selector at the top of the calculator applies a published construction cost index for your state to the 2026 national averages, so the dollar figures move and the material list stays put.

Treat the result as a budgeting range, not a quote. Two metros inside the same state can differ by more than the statewide index suggests, and a single busy contractor can outweigh both. See the full cost index for all 50 states and where the price data comes from.