How to calculate how much gravel you need
Measure the surface area, multiply by the planned gravel depth, and convert the resulting volume into the unit used by your supplier. For a rectangle, volume = length × width × depth. For a circle, first calculate area as π × radius², then multiply by depth. If you already know the surface area of an irregular space, choose Custom area.
The gravel calculator handles US and metric conversions, including the exact relationship of 27 cubic feet = 1 cubic yard. It reports cubic yards, cubic feet, and cubic meters so you can compare the result with the unit used by a quarry or landscape supplier.
Gravel volume vs. gravel weight
Volume answers how much space the gravel must fill. Weight in pounds, US tons, kilograms, or metric tonnes is calculated by multiplying that volume by a loose bulk density. Your measured volume is the more certain result; weight remains an estimate because the actual delivered material may not match a reference density.
Why gravel density varies
Stone type, particle size and gradation, void space, moisture, and compaction all affect bulk density. Caterpillar’s reference table explicitly notes that exact material characteristics require testing. For a large or load-sensitive project, ask the supplying quarry or landscape yard for the density of the exact product and enter it as a custom value.
Optional gravel purchasing buffer
The optional 0%, 5%, 10%, 15%, or custom percentage is simply a purchasing buffer selected by you. It is not an engineering recommendation. The calculator shows the unbuffered required volume separately from the buffered planning quantity.