Square footage is the starting point for pricing flooring, siding, decking, and paving — but most jobsites aren't simple rectangles. This calculator handles rectangles, circles, triangles, and L-shaped sections, adds a waste factor for cuts and overage, and applies your material and labor rates to give you a priced total straight from your field measurements.
28×18 ft outer dimensions with a 10×8 ft notch cut-out. Hardwood at $8.50/sq ft material, $4/sq ft labor, 10% waste.
14 ft diameter circle (radius 7 ft). Pavers $12/sq ft, install $6/sq ft, 12% waste.
2 rectangles: 20×10 ft + 40×12 ft. Asphalt $4.50/sq ft, 8% waste.
For rectangular rooms with straight cuts, use 5–10%. For diagonal or herringbone patterns, use 15%. For tile in irregular rooms, 10–15% is standard. Hardwood in a simple room, 7–8%. Always round up to the nearest full box or bundle.
Divide the L into two rectangles, calculate each, then add them together. Or measure the full bounding rectangle and subtract the notch cut-out. The L-shape option in this calculator does exactly that — enter the outer dimensions and the notch size.
One roofing square covers 100 sq ft. Divide your total gross area (including waste) by 100 to get the number of squares to order.
Use the circle formula: π × radius². For a 12-foot diameter circle, the radius is 6 ft → 3.14159 × 36 = 113 sq ft. This calculator handles circles automatically — just enter the radius.
For a right triangle: ½ × base × height. This works for any triangle where you know the base width and perpendicular height — common for hip roof sections and triangular garden beds.