Stone calculator
Granite Weight Calculator
Granite runs about 165 lb per cubic foot. Enter the area and thickness to see total weight, weight per square foot and how many people it takes.
Your project
A typical kitchen has 40-55 sq ft of countertop.
Most granite is 160-175 lb/ft³. Dark gabbros run higher.
Total granite weight
487
lb
- Weight per square foot
- 10.8 lb
- Thickness
- 0.79 in (2 cm)
- Kilograms
- 221
- Tons
- 0.24
- Installers needed
- 4+ with suction cups and an A-frame
Standard kitchen cabinets carry granite fine. Islands with overhangs beyond 10 inches need corbels or steel; unsupported 3 cm granite cracks under a seated adult.
The shareable link reopens this calculator with your exact inputs.
2 cm versus 3 cm granite
3 cm (1 1/4 inch) granite weighs about 16-18 lb per square foot and is the standard for countertops in the US because it can be installed without a plywood substrate. 2 cm granite weighs 11-12 lb per square foot and needs full plywood support underneath.
A 45 sq ft kitchen in 3 cm granite is roughly 730 lb of stone — which is why it arrives in two or three sections rather than one piece.
Handling and support
Slabs are transported and carried on edge, never flat: a slab carried flat flexes under its own weight and snaps. On site, suction cups and an A-frame cart are standard, and a full-size slab is a four-person move.
For overhangs, the rule of thumb is that 3 cm granite can cantilever about 10 inches unsupported and 2 cm about 6. Beyond that, use steel plates or corbels rather than hoping.
Granite weight by thickness
| Thickness | lb / sq ft | 45 sq ft kitchen |
|---|---|---|
| 1.2 cm | 6.5 | 293 lb |
| 2 cm (3/4") | 10.8 | 487 lb |
| 3 cm (1 1/4") | 16.2 | 730 lb |
| 2" | 27.5 | 1,238 lb |
| 3" | 41.3 | 1,856 lb |
Frequently asked questions
+How much does a granite countertop weigh?
About 16-18 lb per square foot in 3 cm, so a typical 45 sq ft kitchen is 730-810 lb across all sections.
+How much does a full granite slab weigh?
A standard 3 cm slab around 9.5 ft × 5.5 ft is roughly 52 sq ft, or about 850 lb. Jumbo slabs exceed 1,200 lb.
+Can my cabinets hold granite?
Standard well-built cabinets carry 3 cm granite without modification. The concern is always overhangs and unsupported spans, not the cabinet boxes themselves.
+How much does a cubic foot of granite weigh?
About 165 lb, though dark igneous stones sold as granite can reach 180 lb/ft³.