How To Figure Square Feet?

Measure the length and width in feet

Multiply length × width

Square feet = length(ft) × width(ft)

For odd shapes, split into rectangles and add the square feet of each

For a square: square feet = side(ft) × side(ft)

For a rectangle with partial units: convert to feet first (e.g., inches ÷ 12) then multiply

For a circle: square feet = 3.1416 × radius(ft) × radius(ft)

For a triangle: square feet = (base(ft) × height(ft)) ÷ 2

For a trapezoid: square feet = ((base1(ft) + base2(ft)) ÷ 2) × height(ft)

For a polygon: divide into triangles or use a coordinate method, then add areas in square feet

For multiple rooms/areas: compute each area in square feet and add totals