Square Footage Calculator

Square footage is the number almost every construction and real estate decision rests on — material orders, contractor bids, property valuations and tax assessments all start from it. The problem is that most calculators only handle a perfect rectangle, while real rooms are L-shaped, circular, angled or trapezoidal. Forcing those into a rectangle either over- or under-states the area, and the error flows straight into the budget.

Square Footage Calculator models the actual geometry of each room and separates the three numbers that matter: floor area (for flooring and $/sq-ft pricing), wall area (for paint, drywall and wallpaper), and material area with a waste factor (for what you actually buy). Enter measurements in feet, inches, yards, meters or centimeters, add as many rooms as the project needs, and get a consolidated takeoff with optional cost estimates.

Underneath the buttons is the information the system actually requires — what floor area versus wall area means, why the waste factor exists, how unit conversion works — plus practical guidance on reading the result. Everything runs in your browser; nothing is uploaded.

• Six room shapes: Rectangle, square, L-shape, circle, triangle and trapezoid, each computed with the correct geometric formula.
• Unit flexibility: Enter measurements in feet, inches, yards, meters or centimeters — all converted to square feet for consistent totals.
• Floor vs wall area: Add a wall height to get paintable/wall surface area (perimeter x height) separately from floor area.
• Waste / overage factor: Apply a percentage for cut-loss on tile, hardwood and carpet so you order the right amount of material.
• Cost estimation: Supply a rate per square foot to get an instant material cost per room and for the whole project.
• Multi-room projects: Add unlimited rooms and get a consolidated floor, wall, material and cost total.
• Three export formats: CSV for spreadsheets, JSON for code, and a plain text list for quotes and reports.
• Copy or download: Take what you compute without leaving the browser, with nothing uploaded to any server.

1. Pick a room shape. Rectangle, square, L-shape, circle, triangle or trapezoid — the input fields update to match.
2. Enter a room name and unit. Use the unit you measured in; the tool converts to square feet automatically.
3. Fill in the dimensions. Length and width for rectangles, side for squares, large and notch dimensions for L-shapes, diameter for circles, base and height for triangles, and two bases plus height for trapezoids.
4. Add wall height (optional). This unlocks the wall area column for paint and drywall takeoffs.
5. Set waste % and rate (optional). Waste covers cut-loss; rate drives the cost estimate per square foot.
6. Add the room. Repeat for every space in the project to build the full takeoff.
7. Copy or download. CSV for spreadsheets, JSON for code, plain text for documentation.

Example 1 — Rectangular bedroom. Shape rectangle, 12 ft by 10 ft, wall height 8 ft. Floor area is 120 sq ft; wall area is 352 sq ft. Add a 10% waste factor at $4.50/sq ft to see the flooring material cost.

Example 2 — L-shaped living room. Large footprint 16 x 12 plus a 8 x 6 notch. The tool returns 240 sq ft of floor area by summing both rectangles, with wall area from the combined outline.

Example 3 — Circular entry. Diameter 10 ft gives about 78.5 sq ft of floor using pi x (diameter/2) squared — handy for round foyers and silos.

Example 4 — Mixed-unit plan. Measure the kitchen in meters and the hallway in feet; choose the unit per room and the project total still sums correctly in square feet.

Example 5 — Full takeoff. Add every room across an apartment, set a waste factor and a supplier rate, then export the CSV to hand to the flooring contractor.

• Stop forcing rooms into rectangles: Model L-shapes, circles and angles with the right formula, not a guess.
• Separate the numbers that matter: Floor area, wall area and material needed are different figures for the same room.
• Order the right amount: The waste factor turns bare floor area into a realistic material order.
• Budget with confidence: A rate per square foot turns the takeoff into an instant cost estimate.
• Match any consumer: CSV for spreadsheets, JSON for code, plain text for quotes.
• Free and private: No account, no watermark, nothing uploaded.