Gravel Calculator

How to calculate gravel needed

Measure the area, pick a finished depth, convert to cubic yards, then apply waste and compaction. Multiply by density to get tons — the unit most suppliers use for delivery.

1. Measure length and width

   Tape the path, driveway, or bed. For irregular shapes, split into rectangles and add the areas.

2. Choose depth and material

   Depth drives volume; material density drives tonnage. Pea gravel, crushed stone, and crusher run weigh differently per yard.

3. Add waste and compaction

   Order volume = finished volume × compaction × (1 + waste%). Then tons = order yd³ × tons per yd³.

Cubic yards and tons formulas

Example: 20 ft × 10 ft at 3 inches (0.25 ft) → 50 ft³ ÷ 27 ≈ 1.85 yd³. At 1.4 tons/yd³ ≈ 2.6 tons before waste.

Gravel depth guidelines

Tons per cubic yard by material

Densities are approximate bulk figures used for planning. Confirm with your quarry or landscape supplier.

Compaction and waste

Compaction shrinks loose gravel into a denser finished layer. Order loose volume = finished volume × compaction factor × (1 + waste%). Use about 10% waste for typical sites and 1.15 compaction for dense base; leave compaction at 1.0 for decorative stone you will not compact heavily.

How much does a ton of gravel cover?

Roughly 80–100 sq ft at 2 inches and 40–50 sq ft at 4 inches for typical crushed stone. Exact coverage = (324 ÷ depth inches) ÷ tons per yd³. The results panel shows this for your inputs.

Cost estimate

Enter price per ton (preferred when suppliers weigh loads) or price per cubic yard. Estimated cost uses the order quantity after waste and compaction. Delivery and tax are usually separate.

Related tools

Need volume only? Use the cubic yard calculator. For area without depth, try the square footage calculator.

Yards first, then tons

Gravel is ordered in two languages. Landscape yards often speak in cubic yards. Quarries and delivery tickets often speak in tons. The bridge is density: tons equal cubic yards times tons per cubic yard. A common planning range for crushed stone is about 1.4 to 1.5 tons per cubic yard as delivered. Pea gravel is often near 1.4. River rock can be a little lighter. Those are averages. Moisture and the size of the stone move the real ticket. Ask the supplier for the density they bill before you place a large order. This calculator multiplies the density you select or enter. It does not weigh the pile.

The volume underneath that weight is the same geometry as the cubic yard calculator: length times width times depth, converted to yards. A 20 foot by 40 foot driveway at 4 inches deep is 800 square feet times 4 inches, divided by 324, which is about 9.88 cubic yards. At 1.5 tons per yard that is about 14.8 tons before waste and compaction. Four inches is a depth, not a suggestion to skip the division. The cubic yard page stops at the volume. This page continues into weight, bags, waste, and compaction because those are how gravel is bought.

Waste and compaction are different allowances

Waste covers spillage, an irregular edge, and stone that scatters beyond the string line. Compaction covers the fact that a specified finished thickness is thinner than the loose stone you dumped. A 4-inch compacted layer may require more than 4 inches of loose stone. Adding 10 percent waste and another 10 percent for compaction is a planning habit, not a law. If you check both boxes, the allowances stack. Use them when the specification says “compacted thickness” and the site is messy. Skip compaction when you are spreading a loose decorative layer that will not be rolled. Skipping both on a structural base is how a driveway ends up thin in the middle.

Bag products are the same volume sold in small units. Divide the cubic feet you need by the cubic feet printed on the bag. A cubic yard is 27 cubic feet, so a 0.5 cubic foot bag is 54 bags per yard before allowances. Buying a few extra bags is reasonable. Buying tons of bagged stone for a full driveway is usually the expensive way to get the same weight a truck would deliver. The calculator can show the bag count so a small path stays in retail units while a driveway stays in tons.

Depths that match the job

Walkways and decorative beds are often 2 to 3 inches deep. A residential driveway is often planned around 4 to 6 inches of compacted stone, sometimes in more than one layer. A heavier parking pad may need more. Those ranges are starting points from common landscape practice, not a site design. Soil that pumps under load, a missing geotextile, or poor drainage will not be fixed by a slightly thicker number in this form. If the project is structural, use the depth a builder or a specification named, then let the calculator turn that depth into yards and tons.

Measure the area in pieces when the drive is not a rectangle. A straight run plus a parking square is two volumes added together. A curve can be approximated as a rectangle of average width. Several widths averaged along the length beat one width taken at the widest point. Depth that varies because of ruts should be measured in the ruts, not only on the high crown. The stone will disappear into the low spots first.

A path example and a driveway example

A path 30 feet long and 3 feet wide at 2 inches deep is 90 square feet times 2, divided by 324, about 0.56 cubic yards. At 1.4 tons per yard that is under a ton, so bags may be the practical purchase. Add a small waste allowance if the edging is uneven. Do not add a compaction allowance if the path is loose pea gravel that you want to stay loose. The cubic yard calculator would have stopped at 0.56 yards. The extra step here is the weight and the bag math.

The 20 by 40 foot driveway at 4 inches and 1.5 tons per yard was about 9.88 yards and 14.8 tons. Ten percent waste makes about 10.9 yards. Another ten percent for compaction on top of that is about 12.0 yards and about 18 tons at the same density. Round to a quantity the quarry will load, and keep the unrounded figure so you know the pad is not a guess. If the quoted density is 1.35 instead of 1.5, the tonnage falls and the yards do not. Change the density rather than stretching the depth to force a tonnage match.

What the ticket settles

On a full truck, the weight ticket is the number you pay for. The calculator is the number you order against. If they disagree, compare density and moisture before you accuse the measurement. Wet stone is heavier. A ticket that is heavy and a bed that looks thin can both be true if the stone compacted or if the depth was measured loose. Re-measure the finished depth in several places. This page cannot see the truck.

Do not use a fake density to disguise a square-footage mistake. If the area is wrong, the tons will be wrong at every density. Re-measure length and width, confirm depth is in inches, and rerun the volume. The square footage calculator is available when you want the footprint alone. The cubic yard calculator is available when you want volume without a gravel density. Use this page when the question is how many tons to tell the supplier, with the allowances labeled as allowances.

Gravel calculator FAQs