Gravel Calculator

A gravel calculator estimates the volume of material needed to cover an area to a chosen depth. It also estimates weight using a bulk density, helping you compare a project measured in feet or meters with a supplier’s quote in cubic yards, US short tons or metric tonnes.

Use a rectangle for a driveway or path, a circle for a round bed, or Known area when you have already measured an irregular space. Multiple Areas lets each space keep its own dimensions, depth and material density. Optional allowance, pricing and bag controls help turn the base estimate into a purchase plan.

The tool runs in your browser, updates while you edit and keeps full numerical precision until display. Reset restores the labeled 20 × 10 ft example and clears optional pricing and bag settings.

The short answer is volume = area × depth. Measure the ground area, convert depth into a compatible unit, and multiply. To estimate weight, use weight = volume × bulk density.

1. Choose an area shape and enter its dimensions, or enter known area directly.
2. Enter the depth specified for your project. Each dimension and depth has its own unit selector; changing units preserves its physical size.
3. Select a material and verify the density. Presets are estimates; replace them with supplier information when available.
4. Read base volume and estimated weight. Add an allowance or your quoted price if required, then copy or export the calculation.

Need to calculate your project’s area first? Use our Square Footage Calculator, then enter that result under Known area.

Consider a rectangular area 20 feet long and 10 feet wide with a chosen gravel depth of 3 inches. This depth is an example input, not a universal driveway recommendation.

For varying depths, split the driveway into sections and calculate each volume separately. A simple average depth is useful only if it represents the actual area being filled. Site conditions, drainage, loading and the intended layer system determine an appropriate specification; this tool does not design the driveway.

A cubic yard is a volume measuring 3 feet by 3 feet by 3 feet. It contains 27 cubic feet. Calculate volume in cubic feet and divide by 27 to get cubic yards. Do not divide by three: all three dimensions change unit.

For metric measurements, area in m² multiplied by depth in meters gives m³. One cubic foot equals exactly 0.028316846592 m³. Our 50 ft³ example therefore equals 1.4158423296 m³.

A square yard and a cubic yard describe different quantities. An area cannot be converted into gravel volume until a depth is supplied.

Volume alone does not determine gravel tonnage. Multiply cubic feet by density in lb/ft³ to estimate pounds, then divide by 2,000 for US short tons. With metric units, multiply m³ by density in kg/m³ to estimate kilograms, then divide by 1,000 for metric tonnes.

The 5,250 lb example equals 2.625 US short tons, approximately 2,381.3599 kg, or 2.3814 metric tonnes. These units are different; a supplier’s unqualified “ton” needs clarification. This calculator labels the convention wherever a weight estimate or pricing unit appears.

For multiple materials, estimate each area’s weight from its own density and then add the weights. Multiplying combined volume by one material’s density would be wrong when densities differ. The area-by-area breakdown preserves the inputs behind your estimate.

Naturally weathered gravel commonly has rounded edges, while mechanically crushed stone commonly has angular surfaces. Suppliers may use the word gravel broadly, so a material name by itself does not identify its grading, density or suitability for a particular application.

Pea gravel, crushed stone and landscape rock are available as separate selectors here to label your calculation and provide editable starting estimates. Their preset densities are illustrative, rather than certified material specifications. Confirm the exact product and bulk density with the supplier instead of treating the selector as a material recommendation.

First calculate an order quantity: base quantity × (1 + additional percentage ÷ 100). Then multiply by a price in the matching unit. A price per cubic yard must multiply cubic yards, and a price per US short ton must multiply US short tons.

Using 2.625 US short tons, a 10% allowance gives 2.8875 US short tons. At an illustrative $50 per US short ton, material-only cost is $144.38 after rounding the final $144.375 amount. The calculator does not assume a current gravel market price.

The additional allowance does not change the base ground volume. Delivery, installation, taxes, equipment and other expenses are excluded. Currency selection formats your numbers without fetching exchange rates. If different materials have different prices, run separate cost calculations; the combined estimate applies the entered unit price uniformly.

Check a supplier’s minimum order and delivery increments before purchasing. Bulk order quantities are not automatically rounded to a truckload or another delivery unit.

Coverage depends on both area and depth. A 10 × 3 ft pathway at 2 inches deep needs 30 × (2 ÷ 12) = 5 ft³, approximately 0.1852 yd³. At twice the depth, the same area needs twice the volume.

A circular bed uses area = π × radius². Measure radius from the center to the edge, or divide diameter by two. Split more complicated shapes into non-overlapping sections or calculate their area first. Do not include planted spaces or existing structures unless they are actually being filled.

Estimating gravel bags

Enter the actual weight or volume from the product label. Divide the order weight by bag weight, or the order volume by bag volume, and round upward. For example, 5,250 lb requires 105 bags of 50 lb before an allowance. Bag sizes are never assumed; the calculator requires your input and rounds each area’s count separately.

Bulk density includes the voids between stones. It differs from the density of the solid rock itself and varies with grading, moisture and how tightly material is packed. A named material can therefore have more than one reasonable bulk density.

Preset values in this tool are loose-material estimates. If your depth represents a finished compacted layer, multiplying it by a loose density alone does not determine the delivered volume needed to reach that layer. Ask the supplier or project designer for the appropriate loose-to-compacted allowance or specification.

The optional additional percentage is a planning allowance, not a universal compaction factor. Enter a project-specific value rather than assuming that one percentage applies to every material or site. Changing density affects estimated weight; it does not change the geometric volume.