How much does a granite countertop weigh?

Three centimeter (1.25 inch) granite weighs about 17.5 lb per square foot. A typical 96 x 26 inch island run is about 305 lb, and a full 55 sq ft kitchen carries roughly 950 lb of stone spread across the cabinets.

How much does a cubic foot of stone weigh?

Between 145 and 175 lb depending on the type: sandstone about 145, marble 160, limestone 162, granite 168 and slate 174. That is 8 to 10 times heavier than water, which is why small slabs are heavier than they look.

Can my cabinets support granite?

Standard modern cabinets support 3 cm granite without reinforcement; the load spreads to about 18 lb per square foot along the run. Overhangs past 10 inches and heavy stone past 2 cm on old or damaged cabinets are the cases that need brackets.

Why should stone slabs be carried vertically?

Stone is strong when squeezed but weak when bent. Carried flat, a long slab flexes and can crack from its own weight. Carried on edge like glass, the load runs through the strong axis, which is how fabricators transport slabs on A frames.

Stone Weight Calculator: Granite, Marble and Slab Weight

How to calculate stone weight

Volume times density. Convert all dimensions to feet, multiply length x width x thickness for cubic feet, then multiply by the stone density in pounds per cubic foot: granite about 168, marble 160, limestone 162, slate 174, sandstone 145. A typical kitchen countertop run of 96 x 26 inches in 3 cm (1.25 inch) granite weighs about 305 lb, which is why installers come in pairs and why the cabinet layout matters.

Slab weight per square foot by thickness

Material	2 cm (3/4 in)	3 cm (1.25 in)	5 cm (2 in)
Granite	11.0 lb/sq ft	17.5 lb/sq ft	28.0 lb/sq ft
Marble	10.5	16.6	26.6
Quartzite	10.8	17.2	27.5
Slate	11.4	18.1	29.0
Sandstone / flagstone	9.5	15.0	24.1

Figures are computed straight from density and thickness, so they are the weight of the stone itself; add 10 to 15 percent when estimating shipping crates and padding.

Will my floor or cabinets hold it?

Standard kitchen cabinets handle 3 cm stone comfortably: a full 60 sq ft kitchen of 3 cm granite is about 1,050 lb spread across the entire cabinet run, well under structural limits. Floors matter more for freestanding pieces: a 2 inch thick stone dining table top of 4 x 8 ft weighs about 900 lb, concentrated on four legs. Residential floors are rated around 40 lb per sq ft distributed, so point loads like that deserve a look at joist direction or a spreader base.

Moving stone without breaking it or you

Carry slabs vertically, never flat: stone is strong in compression and weak in bending, and a flat carried slab can snap under its own weight. Two people per 150 lb, an A frame or slab dolly beyond that. For flagstone patios and steps, our main stone calculator works in tons for bulk material, while this page is the one for individual cut pieces.