How much gravel do you need?
The amount of gravel you need depends on the area you are filling and the depth of the layer. This calculator estimates volume in cubic feet and cubic yards, plus an approximate weight based on the selected gravel type.
How to use the gravel calculator
- First, choose whether to enter length and width or a total area.
- Next, enter the measurements and select the correct units.
- Then, enter the depth of the gravel layer.
- After that, select the gravel type for an approximate weight estimate.
- Finally, add a 5% or 10% extra allowance (Optional), then select Calculate gravel.
For irregular areas, divide the space into simple shapes, calculate each area separately, and add them together before using the total-area option.
Gravel calculator formula
For a rectangular area measured in feet:
Area = length × width
Convert the depth from inches to feet, then calculate:
Volume (ft³) = area (ft²) × depth (in) ÷ 12
Volume (yd³) = volume (ft³) ÷ 27
Estimated weight (US tons) = volume (yd³) × density (US tons/yd³)
If an extra allowance is selected, it is applied to the volume before estimating weight. One cubic yard equals 27 cubic feet. A US short ton equals 2,000 pounds.
Example calculation
For an area 20 feet long and 10 feet wide, with a 3-inch layer:
- Area: 20 × 10 = 200 square feet
- Volume: 200 × 3 ÷ 12 = 50 cubic feet
- Cubic yards: 50 ÷ 27 ≈ 1.85 cubic yards
- At an assumed density of 1.5 US tons per cubic yard, estimated weight: 1.85 × 1.5 ≈ 2.78 US tons, using the unrounded volume for the calculation.
This example excludes an extra allowance. Actual gravel weight can differ from the estimate.
How deep should gravel be?
Required depth depends on the project, material size, drainage requirements, expected loads, and whether the gravel is used as a decorative surface or a structural base. A garden path and a vehicle driveway may require different layer depths. Follow the project specification or supplier’s guidance rather than relying on a single depth for every use.
Why is gravel weight only an estimate?
Gravel density varies with stone type, particle size, grading, source, and moisture. The calculator uses approximate density values for common materials to estimate weight. These presets are based on published typical material densities and are not universal specifications. If you know your product’s density, choose Custom gravel type and enter the value with its stated unit. The calculator converts that value to US short tons per cubic yard for the weight estimate. For bulk delivery, use the supplier’s density or weight-per-volume figure when available. The extra allowance is optional and does not automatically model engineered compaction requirements
Frequently asked questions
How many cubic feet are in a cubic yard of gravel?
One cubic yard equals 27 cubic feet. Divide a volume in cubic feet by 27 to convert it to cubic yards.
How much does a cubic yard of gravel weigh?
Weight depends on the type and condition of the material. A general planning estimate may use around 1.4 to 1.7 US short tons per cubic yard for common gravel, but specific materials can fall outside this range. Ask the supplier for the product's actual density.
Can I enter metric measurements?
Yes. You can enter length and width in meters or centimeters, total area in square meters, and depth in centimeters. The calculator shows volume in cubic feet and cubic yards to make comparison with common bulk-order units easier.
Does the calculator include extra gravel?
Not by default. Select 5% or 10% under Extra allowance if you want to plan for some waste or additional material. This percentage is a planning adjustment, not a guarantee that it covers the amount needed for compaction or every site condition.
Can I use the estimated weight to place an order?
Use it for planning, then confirm with your supplier. Actual weight depends on the product's density and moisture, and suppliers may sell material by weight, volume, or both.