Calculate granite weight for a slab or countertop from its area or dimensions and thickness, with weight per square foot, in pounds and kilograms.

Prefilled with 3 cm, the most common countertop slab; 2 cm is also common. Change it to your stone’s thickness.

Typical values; a stone’s name or color does not fix its density. Use your supplier’s value if you have it.

Optional settings
Area mode only. Enter the total openings, in the unit selected here.

Adds ordering material; it does not increase the installed surface load.

Granite Weight Formula

The calculator uses one of three forms depending on the solve mode you select.

From dimensions:

Weight = Length × Width × Thickness × Density

From area:

Weight = Area × Thickness × Density

Per square foot (surface load):

Load = Thickness × Density
  • Length, Width, Thickness — slab dimensions, converted to meters
  • Area — net slab face area, converted to m²
  • Density — granite density (default estimate2,700kg/m³, about168.6lb/ft³); internal calculations use kg/m³
  • Weight — total weight in pounds (also shown in kg)
  • Load — weight per unit area in lb/ft² (also shown in kg/m²)

Granite density varies by type and porosity. Use a supplier’s measured density for the specific slab. Presets are illustrative, not classifications by stone color or name. In area mode the optional cutout field subtracts openings before volume is calculated. Ordering overage adds material without changing the installed stone surface load.

Typical Granite Weights and Densities

Use these tables to sanity check your result or to pick a density when the supplier has not given one.

Slab thickness Weight per ft² Weight per m²
2 cm (about0.787 in) ~11 lb ~54 kg
3 cm (about1.181 in) ~16.5 lb ~81 kg
2 in ~28 lb ~137 kg
3 in ~42 lb ~205 kg
Granite type Density (lb/ft³) Density (kg/m³)
Light granite 160 2,560
Average granite 168 2,690
Dense granite 175 2,800
Very dense granite 185 2,960

Example and FAQ

Example: At the default2,700kg/m³, a96in ×26in ×3cm countertop has volume0.0483095808m³ and mass130.436kg (about287.562lb), before cutouts or ordering overage.

How heavy is a standard 3 cm granite countertop? At2,700kg/m³,3cm of stone alone is about16.59lb/ft², or about829.51lb for50ft² before cutouts. Added supports, adhesive and other materials are excluded.

Should I use 2 cm or 3 cm for my calculation? Use what the fabricator quoted. Measure the actual stone thickness; nominal metric and inch sizes are not exact equivalents.

Does the result include the sink cutout? Area mode subtracts the optional total cutout area. Other modes use the dimensions or volume you enter without subtracting openings.

Why does my supplier’s number differ? Stone density, thickness and cutouts vary. Enter the supplier’s density and exact dimensions. This material estimate does not certify structural support or safe lifting.