Stone Weight Calculator

Stone weight = Volume × Density. Volume = Area × Thickness. Area depends on shape: Rectangle: L×W. Circle: πr². Oval: π×(L/2)×(W/2). Triangle: (base×height)/2. Density varies by stone type: Granite 175 lb/ft³ (2.8 g/cm³), Marble 165 lb/ft³ (2.6 g/cm³), Limestone 150 lb/ft³ (2.4 g/cm³). For example, a 36×24×2 inch granite slab has volume 1,728 in³ = 1.0 ft³, weighing 175 lbs. Always factor in density variations — natural stone is not perfectly uniform.

Granite countertops typically weigh 12-15 lbs per square foot at 3/4 inch thick, and 18-22 lbs per sq ft at 1-1/4 inch thick. A typical kitchen island (8×4 ft at 3/4") weighs approximately 350-480 lbs. A full kitchen with 50 sq ft of countertop weighs 600-750 lbs. This weight must be considered for cabinet support. Granite slabs are heavy — a full slab weighs 900-1,200 lbs. Professional handling and reinforced cabinets are essential for granite installations.

Basalt and bluestone are among the heaviest at 180-200 lb/ft³. Quartzite ranges 170-175 lb/ft³. Granite is mid-heavier at 170-180 lb/ft³. The lightest common stones are travertine at 145 lb/ft³ and limestone at 150 lb/ft³. Soapstone at 135 lb/ft³ is relatively light but very dense feel. Engineered quartz (Caesarstone, Silestone) is similar to granite at 170-175 lb/ft³. For landscape boulders, weight is critical for transport and placement equipment requirements.

Landscape stone is typically measured in tons. A cubic foot of most stone weighs 140-180 lbs, so a cubic yard weighs 3,780-4,860 lbs (1.9-2.4 tons). River rock weighs about 2,600-3,000 lbs per cubic yard (less due to air gaps). Crushed stone weighs about 2,400-2,700 lbs per yard. Flagstone: a 2-inch thick piece covering 1 sq ft weighs 23-30 lbs. A 4×8 ft patio at 2-inch thick with flagstone weighs 1,840-2,400 lbs total. Always order 10-15% extra for breakage and fitting.