Gravel Calculator
Add up to three areas, enter each depth, then adjust the material density and extra percentage.
Gravel volume formula
For a rectangular area, cubic feet = length in feet × width in feet × depth in inches ÷ 12. There are exactly 27 cubic feet in one cubic yard, so divide adjusted cubic feet by 27.
Multiple areas and shapes
Calculate each section separately when a project has different depths or shapes. Circle area is πr², triangle area is base × height ÷ 2, and a ring subtracts the inner circle area from the outer circle area. The result lists every section before adding them.
Waste, compaction, and density
The extra percentage is a user-set planning allowance, not an automatic recommendation. Density also varies by aggregate type, particle size, moisture, and compaction. The initial 1.5 tons per cubic yard is only a replaceable example; use a supplier or project specification for purchasing.
Bulk and bag cost comparison
Optional pricing compares estimated tons at one bulk price plus delivery against whole bags at a stated cubic-foot volume. Taxes, minimum orders, partial-ton billing, pallet deposits, and supplier-specific coverage are outside the calculation.
Planning estimate only
Irregular ground, settlement, excavation tolerance, drainage design, and structural requirements can change the actual order. Keep the section dimensions and assumptions with your estimate, and confirm final quantities with the material supplier or project professional.
Frequently asked questions
How do I calculate how much gravel I need?
Calculate each area's square feet, multiply by depth in feet, add the section volumes, then divide cubic feet by 27 for cubic yards. Add only the waste or compaction allowance you choose.
How many cubic yards is a 10 by 20 foot area at 3 inches deep?
The volume is 10 × 20 × 3/12 = 50 cubic feet. Divide by 27 to get about 1.85 cubic yards before extra material.
How does the calculator estimate tons?
It multiplies adjusted cubic yards by the density you enter in tons per cubic yard. Gravel density varies with material, moisture, grading, and compaction, so replace the planning value with your supplier's figure.
Can it add several shapes?
Yes. Enter up to three rectangles, circles, triangles, or rings. Each section can have its own depth and remains visible in the final estimate.
How does bulk versus bag pricing work?
Enter all four optional pricing values. Bulk cost equals estimated tons times price per ton plus delivery. Bag cost rounds required bag count up to a whole bag.