The weight of marble is typically measured by its density or its weight per square foot/square meter for specific thicknesses.
The Short Answer
Marble weighs approximately 162 pounds per cubic foot (lb/ft³) or 2,600 kilograms per cubic meter (kg/m³).
This is a standard average, but the exact weight can vary slightly depending on the specific type of marble and its mineral composition.
Detailed Weight Calculations
To make it practical for projects, here is the weight calculated for common slabs and tiles.
By Volume
Per Cubic Foot: ~162 lbs (~73 kg)
Per Cubic Meter: ~2,600 kg (~5,732 lbs)
By Area (for slabs and tiles)
This is the most useful measurement for countertops, flooring, and other applications.
| Thickness | Weight (per sq. ft.) | Weight (per sq. meter) |
|---|---|---|
| 1 cm (3/8 inch) | ~12-14 lbs | ~62-68 kg |
| 2 cm (3/4 inch) | ~25-28 lbs | ~124-136 kg |
| 3 cm (1 1/4 inch) | ~37-42 lbs | ~186-204 kg |
Note: 2 cm and 3 cm are the most common thicknesses for countertop.
Why is Marble Heavy?
Marble is a dense stone because it is formed under immense heat and pressure deep within the Earth's crust (a process called metamorphism). This process recrystallizes the original limestone, creating a tight, interlocking structure of calcite or dolomite crystals with very little porosity (empty space).
Example Calculations
A standard kitchen countertop slab:
Size: ~ 9.5 feet long x 5.5 feet wide = 52.25 square feet
Thickness: 3 cm (1 1/4 inch)
Weight: 52.25 sq ft x ~40 lbs/sq ft = ≈ 2,090 pounds (almost 1.05 US tons).
A box of floor tiles:
Tile Size: 24 x 24 inches (2 sq ft each)
Thickness: 2 cm (3/4 inch)
Tiles per box: 10 tiles
Total Area: 20 sq ft
Box Weight: 20 sq ft x ~27 lbs/sq ft = ≈ 540 pounds.
Important Considerations
- Variations: The weight can vary by about 5% depending on the specific quarry and the amount of impurities (like silica or serpentine) in the marble.
- Supports & Structure: Due to its significant weight, it is crucial to ensure that cabinets and floor structures are built to support the load of a marble countertop or floor.
- Professional Advice: Always confirm the exact weight with your supplier for the specific marble variety you have chosen, as this is critical for logistics, installation, and structural safety.
In summary, while marble is beautiful, it is also very heavy, and its weight is a major factor to consider in any project.
