Area
Rectangle = length × width
Circle = π × (diameter ÷ 2)²
Triangle = base × height ÷ 2
Gravel volume and purchase planning
Gravel Calculator
Calculate gravel for driveways, paths, garden beds, drainage areas, and other measured spaces. Add multiple areas, enter the depth you are using, and compare cubic yards, tons, bags, or material cost from your supplier.
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Enter your gravel measurements
Measurements stay in this browser. No account, address, or location is required.
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Calculation details
Review each area, the combined volume, extra material, and purchase rounding.
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How gravel volume is calculated
Every area is converted to one internal unit before volumes are added.
Volume
Area volume = area × depth
Base volume = sum of area volumes
Adjusted volume = base × (1 + extra % ÷ 100)
Purchase quantity
Bags = round up(adjusted volume ÷ label volume)
Bulk order = round up to supplier increment
Weight = volume × entered density
1 ft = 0.3048 m1 in = 25.4 mm1 yd³ = 27 ft³1 m³ = 1,000 L
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Worked example
This example demonstrates the formula. Its depth, extra percentage, and supplier values are examples—not recommendations.
Driveway20 ft × 30 ft
Depth4 in = 0.333… ft
Base volume200 ft³ = 7.41 yd³
With 10% entered8.15 yd³
If a supplier density is entered, the calculator converts the adjusted volume to the selected density unit. Density varies by rock type, grading, moisture, and supplier; no universal ton-per-yard value is assumed.
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Important assumptions
This is a material planning estimate, not site, drainage, engineering, or construction advice.
- Confirm the depth, base preparation, geotextile, grading, access, and project requirements from an appropriate plan or qualified source.
- Gravel density depends on material, moisture, compaction, and supplier basis. Enter density only when you have a relevant supplier value.
- The calculator applies only the extra percentage you enter. It does not infer settling, compaction, rutting, erosion, or spillage.
- Bag volume, bulk price, order increments, and package terms must come from the selected product or supplier.
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Bulk, bags, tons, and cost
Commercial outputs stay separate from the geometric volume so their assumptions remain visible.
Bulk weight is calculated only from the density you enter. Bag count uses the volume printed on the package or manufacturer data sheet and rounds up after all areas and extra material are combined. Cost uses only the price you enter and excludes delivery, minimum-load fees, tax, labor, equipment, base materials, edging, geotextile, and disposal.
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Frequently asked questions
Answers describe this calculator’s formulas and boundaries.
How deep should gravel be?
This calculator does not recommend depth. Enter a depth selected for your project, material, base, traffic, drainage, and local requirements.
How do I calculate gravel for a driveway?
Measure the driveway as one or more rectangles, enter the planned depth, and review the combined volume before adding supplier density or purchase information.
How many tons of gravel do I need?
Enter a supplier density in tons per cubic yard, pounds per cubic foot, or kilograms per cubic meter. The result uses that entered value; it does not apply a universal density.
Can I use bags instead of bulk gravel?
Yes. Select Bags and enter the volume printed on the package or product data sheet. The calculator rounds the adjusted total up to whole bags.
Does the result include compaction or settling?
No. Only the extra percentage you enter is applied. Confirm any compaction or settling allowance with the supplier or project professional.
Does cost include delivery?
No. Cost uses only the material price you enter. Delivery, minimum-load fees, tax, labor, and other project costs remain outside the calculation.
Formula reviewed: 2026-09-01
Exact length and volume conversions follow NIST definitions. Weight requires entered supplier density; no gravel density or price is hard-coded.