How to Calculate Square Footage for Kitchen Countertops

Are you planning a kitchen remodel or new construction? Do you need to select a countertop surface but don't know what your budget is? Calculating the square footage of your solid surface and stone countertops is the first step in getting an estimate of your project. To get an accurate estimate, you need to have all the necessary information. You will need a detailed diagram (plan view) of all the work, including the location of each cabinet, the total length and width of the cabinets, the walls, and the location of the hob, sink, refrigerator, and dishwasher. It's helpful to take notes on the diagram as you go.

Shade and number each countertop, mark the radius, corners, walls, edges to be polished, and where the joints should be located. This will help you stay organized and increase the precision and accuracy of your estimates. A typical granite slab measures 9 feet x 5 feet, so it's not recommended to make countertops larger than 100 inches without a seam or without consulting the manufacturer for exact slab sizes. You should also consider where the hob, sinks, and dishwasher are located - seams should not be placed on dishwashers.

To calculate square footage, multiply length by width in inches and divide by 144%. Kitchen-base cabinets are generally 24 inches deep - this is the case with our sample diagram. To that dimension (2) we must add the 1 ¾ cantilever on the exposed edges, increasing the depth of the top by 24 to 25 ¾. To simplify math, we normally round up to 26. Splash protectors help make the transition from countertop to wall and protect against spills that accumulate behind countertops and against walls.

Mark dotted lines on the diagram where splashes should go and number them. Splash protectors can vary in height so it's important to confirm final dimensions with the customer depending on their desired look. For our example, we'll assume that they want a standard 4-inch splash guard look - splash protectors tend to be fragile when manufactured and transported because of their tightness so they are restricted to 80 in length. The meter will determine the best location of seams and confirm with the customer where they should be placed. Make splashes as long or as short as needed for calculations.

Installation of splash protectors is usually done in areas where countertops are attached to walls but always confirm with customer where they want them placed - for our example, splashes will only extend along countertops adjacent to walls. Therefore there will be splashes along 74-inch countertop and 108-inch sink. To calculate total square feet of work add up total square feet of countertop and splash guard - total square meters of project = 49 sf. Rounding up, total linear footage of work for edgework costs = 22 linear feet (round up). Add up all totals (materials, edges, miscellaneous costs) to find total estimate. In some cases customer may prefer that a seam be placed in certain place or that there be no seam - in all these cases final shape of piece will not be rectangular but more likely L-shaped with any L-shaped part it's most likely “scrap material” - waste material is any material that is not part of final part but has been cut and discarded to achieve L shape or any shape that is not rectangular - waste material is included in cost of material but not in edges or miscellaneous costs. Let's use L-shaped piece to demonstrate - calculate linear edge as done in first example - if don't have actual dimensions of finished part minus waste use perimeter of waste area as measurement - diagram can provide dimensions of linear edges or obtain from customer - if so use figures to calculate total length and cost of quarry - if not simply use perimeter of waste area as estimated edge length. This estimate will work for pieces of any size as long as remember to use longest width and longest length - as seen in following example part is not L-shaped but still fits into 80 x 40 category so material costs would be same - without knowing length of each side also calculate linear footage same way. You may also need to calculate waste material involved in radial parts - follow same steps for material - in diagram below part measures 26 inches in diameter so length = 26 x 3.14 = 81.64 inches (round up) = 7 feet (round up).

Width = 26 x 3.14 = 81.64 inches (round up) = 7 feet (round up). Total square feet = 49 sf (rounded up).Add up all totals (materials, edges, miscellaneous costs) to find total estimate. Calculating square footage for kitchen countertops can seem daunting but with a detailed plan view diagram and some simple math you can get an accurate estimate quickly.

Curt Cuneo
Curt Cuneo

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