Countertop Square Footage Calculator

How it works

straight or L top = (run 1 + (run 2 − depth)) × depth · island = length × width · backsplash = (run 1 + run 2) × height · slabs = ⌈total × 1.15 ÷ 5.12 m²⌉

Fabricators price stone and quartz countertops by the square foot or square metre of finished surface, so add up every rectangle: the main run, the second leg of an L-shape (minus the corner square already counted), any island and the backsplash strip. Standard base-cabinet countertops are 25–25½″ (about 64 cm) deep including the overhang, and islands are commonly 36–42″ (90–107 cm). Quartz jumbo slabs are about 126 × 63″ (3.2 × 1.6 m); the 15% allowance covers cut-outs, seams and grain matching. Edge profiles, sink and cooktop cut-outs are often charged per linear foot or per piece on top.

Worked example

An L-shaped kitchen with a 3 m main run, a 1.5 m second run, 64 cm depth and a 10 cm backsplash: countertop = (3 + 1.5 − 0.64) × 0.64 = 2.47 m², backsplash = (3 + 1.5) × 0.10 = 0.45 m², total 2.92 m². The finished front edge is 3.86 m, it fits in 1 jumbo slab, and at $300 per m² installed it costs about $876.12.

Sources: NKBA — Kitchen planning guidelines · Natural Stone Institute — countertop resources

Frequently asked questions