How To Determine Square Footage For Granite Countertops. Multiply this number by the width then divide by 144 to get the total square footage estimate. For example, say the length of the countertop is 108” and the depth of the standard countertop (on a 24” deep cabinet) is 25 ½”;
÷ 144 = total square feet: 144 = square footage of your countertops. Use the form below to calculate the total square footage of your countertops.
Multiply length in inches times width in inches and divide it by 144.
Divide 4,320 by 144 to convert to square feet: Multiply your total length by 26, the width in inches of standard countertops, to find total countertop area in square inches. You know what they say about measuring twice! 144 = square footage of your countertops.