Calculator

Length (ft)

Width (ft)

Depth (in)

Density (lb/ft³)

Price per Ton ($)

Cubic Yards

Estimated Weight

tons

Estimated Cost

River rock density depends on the stone size and how tightly it settles — smaller stone packs denser than large cobble. The default here (100 lb/ft³) is a typical mid-range figure; check the bag or supplier spec sheet for your specific size and swap it in for an accurate weight.

Enter length, width, and depth to calculate river rock volume, weight, and cost.

How to Use the River Rock Calculator

Length, width, and depth define the area to cover; density and price per ton are both editable, with price defaulting to 0 for a quantity-only result.

cubic feet = length (ft) × width (ft) × (depth (in) ÷ 12)
weight = cubic feet × density (lb/ft³)

River rock is sold in size grades — from pea-sized pebbles up to 4-6 in cobble — and the grade changes how it settles. Smaller stones fill gaps between each other more efficiently, so a bed of pea gravel actually weighs more per cubic foot than a bed of large cobble with the same footprint. That's the opposite of what intuition suggests, and it's exactly why the density field here is editable rather than fixed at one number.

Depth Depends on the Job

A decorative border or dry creek bed typically runs 2-3 in deep; a drainage or erosion-control application often calls for 4 in or more to actually do its job rather than just look good. Check the supplier's guidance for your specific use before locking in a depth.