Stone Weight Calculator

The weight of a piece of stone is just its volume times the density of that particular stone, but both parts trip people up. Volume is straightforward if you keep units together: multiply length, width, and thickness in inches, then divide by 1,728 to convert cubic inches to cubic feet. Multiply that by the stone’s density in pounds per cubic foot and you have the weight.

Density is what makes the difference between stones that look similar but feel very different. Granite runs about 168 pounds per cubic foot, marble a touch more, slate heavier still, while limestone and sandstone are lighter at roughly 145 to 150. That spread means a marble slab can outweigh a sandstone slab of the same size by 15 percent or more, which matters when you are deciding whether a countertop, hearth, or paver is a one-person lift.

This is mainly a safety and planning number. A single person should not try to move much beyond 150 pounds of awkward slab without help or a dolly, and trailers, shelving, and cabinets all have limits worth checking against the result. For countertops, knowing the weight up front tells you whether the base cabinets need extra support and how many hands the install will take. The figure assumes solid stone; honed, polished, or hollow pieces vary a little, so treat it as a close working estimate rather than a certified value.