Square Footage Calculator — Area in Square Feet

    Calculate the square footage of any space or area. Supports rectangles, circles, triangles, trapezoids, and L-shapes. Use it for rooms, yards, flooring, landscaping, painting, and any project where you need to know the area.

    Tips

    • • 1 square yard = 9 square feet. Divide square feet by 9 to get square yards.
    • • 1 acre = 43,560 square feet.
    • • For rooms, measure the longest length and width. For irregular rooms, break into rectangles and add them up.
    • • Round up when ordering materials — always better to have a little extra than not enough.

    Estimates only — measure twice, calculate once.

    Example Calculation

    Measuring a 12×14 foot room? That's 168 square feet, or about 18.7 square yards. For a 10-foot diameter circular patio, the area is 78.5 square feet. Knowing your exact square footage is the first step for ordering flooring, paint, carpet, tile, or any material sold by area.

    Quick Reference — Common Room Sizes

    Room SizeSquare FeetSquare Yards
    8×10808.9
    10×1010011.1
    10×1212013.3
    12×1416818.7
    14×2028031.1
    20×3060066.7

    Frequently Asked Questions

    How do I calculate square footage?

    Multiply the length by the width in feet. A 10×12 room is 120 square feet. For circles, use the formula: π × radius². For triangles: ½ × base × height.

    How many square feet are in a square yard?

    9 square feet per square yard. Divide your square footage by 9 to convert.

    How do I measure an L-shaped room?

    Break it into two rectangles. Measure each one separately, calculate the area of each, and add them together.

    How many square feet are in an acre?

    43,560 square feet per acre. A typical suburban lot of ¼ acre is about 10,890 square feet.

    How do I calculate square footage for paint?

    Measure the wall perimeter (add up all wall lengths), multiply by ceiling height, then subtract door and window openings. A standard door is about 21 square feet, a window about 15 square feet.

    Typical Results

    Bedroom(typical)100–200 sq ft
    Living room(typical)200–400 sq ft
    2-car garage(typical)400–600 sq ft
    Average home(typical)1,500–2,500 sq ft

    💡 Measure wall to wall at floor level. If the room isn't rectangular, measure longest and widest points.