The phrase represents a tool or method used to determine the volume or weight of river rock necessary to cover a specified area. This typically involves inputting the dimensions of the area to be covered (length, width, and desired depth of the rock layer) into a formula or online application that performs the calculation. For example, one might input a length of 10 feet, a width of 5 feet, and a depth of 2 inches to ascertain the required quantity of river rock.
Accurately estimating material requirements minimizes waste, reduces project costs, and ensures adequate coverage for landscaping or construction purposes. Historically, individuals relied on manual calculations and estimations, often leading to inaccuracies. The advent of these calculation tools streamlines the process, providing a more precise assessment and saving both time and resources.