Gravel Calculator - Cubic Yards, Tons, Bags & Cost

How to use it

1. Pick the shape of the area: a rectangle, a circle, a triangle, or enter the square footage directly.
2. Enter the measurements in feet. For a circle use the diameter, for a triangle the base and height.
3. Set the depth in inches. Use a preset, 2 in for a path, 3 in for ground cover, 4 in for a driveway layer, 6 in for a heavy base, or type your own.
4. Choose the gravel type. It sets an approximate density so the tool can give you tons as well as cubic yards.
5. For crusher run or base, turn on compaction so you order enough to pack down to depth.
6. Leave the overage at 10 percent or adjust it for a tricky site.
7. Optional: add a price per cubic yard, per ton or per bag, a bag size, a delivery fee and a truckload capacity.
8. Read the paired headline, cubic yards and tons, then the full breakdown below.

At a glance

• Pea gravel path, 40 ft x 3 ft at 2 in deep, 10% overage, $45 per cubic yard: 120 sq ft, 20 cu ft, about 0.81 cubic yards and 1.14 tons. Roughly 44 half-cubic-foot bags, or about $37 in bulk.
• #57 stone driveway, 20 ft x 40 ft at 4 in deep, priced per ton at $28, 15 cu yd truck: 800 sq ft, about 10.9 cubic yards and 15.2 tons, one truckload. Material about $426 by weight, plus delivery.
• River rock bed as a 10 ft circle at 3 in deep, 10% overage: About 78.5 sq ft, 0.80 cubic yards and 1.12 tons. Order by the yard for a bed this size rather than by the bag.

How the math works

The area comes from the shape you pick: a rectangle is length times width, a circle is pi times the radius squared, a triangle is half the base times the height, or you enter the square footage directly. Depth is converted from inches to feet by dividing by 12, then volume in cubic feet is area times depth in feet. Cubic feet divided by 27 gives cubic yards, because a cubic yard is 3 ft by 3 ft by 3 ft. Overage multiplies the volume by one plus the waste percent, 10 percent by default, for spillage, uneven ground and settling. For crusher run and base, an optional compaction allowance (20 percent by default) is layered on top, because material that packs down needs more loose volume to finish at the depth you want. Tons are cubic yards times the material density in tons per cubic yard, which is approximate and varies by moisture and gradation. Bags are the final cubic feet divided by the bag size, rounded up. Truckloads are cubic yards divided by the truck capacity, rounded up. Cost matches how your supplier sells it, per cubic yard, per ton or per bag, with an optional flat delivery fee.

1. 1. Find the area in square feet

   Measure the footprint. A rectangle is length times width, so a 40 ft by 3 ft path is 120 sq ft. A circle is pi times the radius squared, so a 10 ft diameter bed is about 78.5 sq ft. A triangle is half the base times the height. For an odd shape, break it into rectangles and add them, or measure the square footage another way and enter it directly.

2. 2. Convert the depth to feet

   Depth is measured in inches but volume needs feet, so divide the inches by 12. A 3 in layer is 0.25 ft; a 4 in driveway layer is 0.333 ft. This one conversion is the most common place a gravel estimate goes wrong: multiply square feet by inches and you overstate the volume by twelve times.

3. 3. Multiply to cubic feet

   Volume in cubic feet is area times depth in feet. 120 sq ft at 2 in is 120 x 0.1667 = 20 cubic feet. This is the raw amount of space the gravel has to fill before any allowance for waste or compaction.

4. 4. Divide by 27 for cubic yards

   Bulk gravel is sold by the cubic yard, and a cubic yard is 27 cubic feet (3 ft on each side). So 20 cubic feet is 20 / 27 = 0.74 cubic yards. As a rule of thumb, one cubic yard covers about 100 sq ft at 3 in deep.

5. 5. Add overage for spillage and settling

   Order a little more than the bare volume for what spills off the truck, works into soft ground, and settles over the first weeks. Ten percent is a sensible default, so 0.74 cubic yards becomes 0.74 x 1.10 = 0.81 cubic yards. Raise it for a long haul across a lawn or a very uneven site.

6. 6. Add compaction for base gravel

   Crusher run and base gravel are meant to pack down to a hard surface, and packed material takes up less room than loose, so you order extra to finish at the depth you want. A 20 percent compaction allowance is common. It only applies to material that compacts, so the toggle is shown for base and crusher run, not decorative stone.

7. 7. Convert cubic yards to tons

   Suppliers often price and weigh gravel by the ton, not the yard, so you need the weight too. Tons are cubic yards times the material density in tons per cubic yard. Pea gravel and #57 stone run about 1.4, crusher run and decomposed granite about 1.5, sand about 1.35. So 0.81 cubic yards of pea gravel is about 0.81 x 1.4 = 1.14 tons. These densities are approximate and shift with moisture.

8. 8. Work out bags, truckloads and cost

   Bags are the final cubic feet divided by the bag size (a bag is often 0.5 cubic feet), rounded up, so 22 cubic feet is 44 bags. Truckloads are cubic yards divided by the truck capacity, rounded up. Cost matches how it is sold: cubic yards times the yard price, tons times the ton price, or bags times the bag price, plus any flat delivery fee.

Worked scenarios, start to finish

Real jobs with the numbers carried all the way through, so you can see how the estimate is built and check your own figures against them.

The judgement calls a pro makes

Decisions the tool cannot make for you, and how someone who does this for a living thinks them through.

Order in the unit your supplier sells

Some yards price and weigh by the ton, others by the cubic yard, and bagged stone is by the bag. The tool gives you all three so you can match the quote. Ordering by volume when the supplier bills by weight, or the reverse, is where a job goes over budget, because the conversion rides on a density that is only approximate.

Pick the depth by what the gravel does

A decorative path or a top-up over existing stone runs about 2 in. General ground cover and drainage beds want about 3 in. A driveway is built in layers of about 4 in each. A heavy base under pavers or a shed footing can be 6 in or more. Deeper is not always better: too deep and loose stone never firms up underfoot.

Add compaction for anything structural

Crusher run and base gravel are meant to be packed with a plate compactor, and packed stone occupies less volume than loose, so order about 20 percent extra to finish at the depth you want. Decorative stone that stays loose does not need it. When in doubt, if you will run a compactor over it, turn compaction on.

One layer or two on a driveway

A proper gravel driveway is rarely one material. The usual build is a coarse base (crusher run or larger stone) compacted for strength, then a #57 or decorative top for the finish. Estimate each layer on its own pass through the tool, with compaction on for the base and off for the loose top, then add the orders.

Delivery minimums and why bulk beats bags

Bulk yards usually have a minimum load and a delivery fee, so a tiny order can cost more per yard than a big one. Bagged stone avoids the fee but costs far more per cubic foot and is a lot of lifting. The rough crossover is about one cubic yard, which is roughly 54 half-cubic-foot bags. Past that, bulk almost always wins on price and effort.

Treat the tonnage as an estimate, not a ticket weight

Density shifts with moisture, gradation and how the stone was screened, so the tons here are an estimate, not the exact figure on the scale ticket. Wet material weighs more. If the supplier bills by weight, expect the delivered tonnage to land within a reasonable margin of this number, not exactly on it.

Common mistakes, and the fix

• × Forgetting to convert the depth from inches to feet.

  ✓ Divide the depth in inches by 12 before multiplying. Three inches is 0.25 ft, not 3. Skip this and you overstate the volume by twelve times.

• × Ordering by volume when the supplier sells by weight.

  ✓ Match the unit on the quote. The tool gives cubic yards and tons together, so you order in the same unit the yard bills, and the density conversion is done once, not guessed at the counter.

• × Ignoring compaction on crusher run and base gravel.

  ✓ Turn on the compaction allowance for material you will pack down. Order only the loose volume and the finished, compacted layer ends up shallower than you planned.

• × Buying the exact volume with no overage buffer.

  ✓ Keep a waste factor, about 10 percent. Gravel spills off the truck, works into soft ground and settles, and coming up short means a second delivery fee for a fraction of a yard.

• × Using bag math for a bulk-sized job.

  ✓ Once you pass about a cubic yard, switch to a bulk order. A driveway priced in bags is hundreds of sacks, far more money and lifting than a single delivered load.

• × Treating the estimated tons as the exact scale weight.

  ✓ Read the tonnage as approximate. Density moves with moisture and gradation, so the delivered ticket will be close but not identical, especially after rain.

Material and unit specifics

Pea gravel

Small, smooth, rounded stone (about 3/8 in) for paths, dog runs and decorative beds. Approximately 1.4 tons per cubic yard. It stays loose and rolls, so it suits flat areas at 2 to 3 in, not steep drives. Bulk is roughly $30 to $60 per cubic yard; bagged runs about $4 to $8 for a half-cubic-foot bag.

#57 / 3/4" crushed stone

Angular, washed stone about 3/4 in with the fines screened out, so it drains freely. About 1.4 tons per cubic yard. The workhorse for driveways, drainage and as a base under pavers or pipe. Bulk is roughly $30 to $55 per cubic yard. It does not compact tight because there are no fines to lock it.

Crusher run / base gravel

Crushed stone mixed with stone dust (fines), so it packs to a hard, stable base under driveways, sheds and patios. About 1.5 tons per cubic yard. Because it compacts, order about 20 percent extra to finish at depth. Bulk is roughly $25 to $45 per cubic yard, often the cheapest stone by the yard.

River rock

Smooth, rounded decorative stone in larger sizes (1 in and up). About 1.4 tons per cubic yard. Used for dry creek beds, borders and low-maintenance beds. Keep it shallow, 2 to 3 in, or the larger stones sit proud and shift underfoot. Bulk is roughly $40 to $100 per cubic yard depending on size and color.

Decomposed granite

Fine, crushed granite that packs into a firm, natural path or patio surface. About 1.5 tons per cubic yard. Spread at 2 to 3 in and compacted; a stabilized version holds together better on slopes. Bulk is roughly $40 to $80 per cubic yard. It compacts, so consider an allowance for structural use.

Sand

Bedding and paver-base sand, and mason or fill sand. About 1.35 tons per cubic yard dry, more when wet. Used as a leveling layer under pavers and a bedding for pipe. Bulk is roughly $25 to $40 per cubic yard. Because it holds water, delivered weight can run noticeably above the dry estimate.

Density is approximate

Every tons-per-cubic-yard figure here is a dry, loose approximation inside the range suppliers publish (about 1.3 to 1.5 for common gravels). Moisture, how finely the stone is crushed, and how it settles all move the real weight. For a large order, confirm the density with your supplier or use the custom option to enter theirs.

Bags versus bulk

A bagged stone is often 0.5 cubic feet, so it takes 54 bags to make a cubic yard (27 cubic feet). Bags cost far more per cubic foot and avoid a delivery fee, which suits a small top-up. A bulk load is cheaper per yard but carries a minimum and a delivery charge. The crossover is around a cubic yard.

Reading your result

Read the paired headline first: cubic yards and tons are the same gravel described two ways, so you can order in whichever unit your supplier uses. The cubic-yard figure already includes your overage, and the compaction allowance too when it applies. Tons come from an approximate density, so treat the weight as a close estimate rather than an exact scale reading. Bags show what the same job would cost in sacks, which is mostly useful for deciding when to switch to bulk. Cost is only ever the price you enter, so the estimate is as good as your quote, and the delivery fee is a flat line on top of the material.

Limitations

• This is an estimate, not a quote. It does not know your supplier's exact density, load minimum, or delivery pricing.
• Densities are approximate dry figures. Moisture, gradation and settling move the real delivered weight, sometimes by a noticeable margin.
• It assumes a uniform depth over the whole area. For a sloped or dished site, average the depth or split it into sections.
• It sizes one material and one layer at a time. For a layered driveway, run each layer separately and add the orders.
• The compaction allowance is a general 20 percent rule, not a substitute for a specified compacted-depth build to an engineer's detail.

Frequently asked questions

How many tons are in a cubic yard of gravel?

For common gravels, about 1.4 tons per cubic yard: pea gravel and #57 stone are roughly 1.4, crusher run and decomposed granite about 1.5, sand about 1.35. So a cubic yard of pea gravel weighs around 1.4 tons (2,800 lb). These are approximate dry figures and rise when the material is wet.

How much gravel do I need for a driveway?

Measure length times width for the area, use about 4 in per layer, and divide the volume by 27 for cubic yards. A 20 ft by 40 ft driveway (800 sq ft) at 4 in is about 9.9 cubic yards, or 10.9 with 10 percent overage, roughly 15 tons of #57 stone. A full build usually adds a compacted base layer underneath, so estimate the base and top separately.

How deep should gravel be?

It depends on the use. A decorative path or a top-up is about 2 in, general ground cover and drainage beds about 3 in, a driveway is built in 4 in layers, and a heavy base under pavers or a structure can be 6 in or more. Too shallow and the ground shows through; too deep and loose stone never firms up underfoot.

Is it cheaper to buy gravel in bags or in bulk?

Bulk is cheaper per cubic foot once you need more than about a cubic yard, which is roughly 54 half-cubic-foot bags. Bags avoid a delivery fee and suit a small top-up, but for a driveway or a large bed the bagged price and the lifting add up fast, so a delivered bulk load almost always wins past that crossover.