Start by Thinking Like a Stone Cutter

You just take the Length x Width of each section, and add it together.
For our U-shaped Counter-top example, we would measure it like this:

Piece A: 62.5” x 25” = 1562.5”
Piece B: Same size as A in this case, so 1562.5”
Piece C: 125” x 25” = 3125”
1562.5”
+1562.5”
+3125”
=6250 square inches

Now, we don’t buy these materials by the square inch so we will need to convert that number into square feet.

A square foot is 12” x 12” = 144. So let’s divide 6250 by 144 to get our final square footage of 43.403.

We always round up when measuring so the final measurement would be 44 square feet.

Even though not all counter tops come in rectangular shapes, the principles of measurements remain roughly the same.

If you wanted a corner sink or a ledge like the example below and to the left, the fabricators will try to cut as much as possible into one solid piece. Measure the center section as if it was a square piece.

The curvy shape below will be measured from its widest point and by length. 

1. The average slab size is 120×55” (or about 41 square feet). Some stone types come in jumbo slabs as well. This is important to know because counter-top materials are sold by the slab. Unless you have a small kitchen, you’ll likely need 1.5 slabs. Some countertops are sold by the half-slab, depending on the color. If your color doesn’t come in half slabs and you need 1.5 for your kitchen. All granite is sold at AG by the sq ft.

2.  Don’t forget the backsplash. If you decide to have a backsplash from the same materials as the countertop, plan for an extra 4-inch-wide section across the length of the countertop. If you only need 1.5 slabs like mentioned above, you can use the extra half slab for the backsplash.

3. Don’t forget to plan for labor and fabrication costs! Labor is calculated by the square footage of your finished countertop, and additional costs such as undermount sinks, special edges, curves, and backsplashes need to be accounted for.