Calculation details
Planning estimate only. Verify dimensions, waste, coverage, product specifications, and local requirements before purchasing materials.
This tool runs in your browser. Your calculator inputs and results are never transmitted to us or to ad/affiliate partners. Ads and sponsored links may set third-party cookies to serve and measure them, but they never receive your calculation values. If you explicitly save a scenario, its permitted fields stay in local browser storage until you clear them. See our Privacy Policy.
Use this result
Share the current inputs or ask ChatGPT to explain the calculation in context.
What does this calculator estimate?
A square footage calculator totals the area of up to two spaces, applies a waste factor, and converts to square yards, square meters, and acres — with an optional material cost. Enter the dimensions to calculate.
- Total = area1 + area2
- 1 sq yd = 9 sq ft; 1 acre = 43,560 sq ft
- sq m = sq ft × 0.09290304
What square footage is used for
Square footage is the standard measure of floors, walls, and lots in the US — used for flooring, paint, real-estate listings, and material purchasing. Converting to other units helps compare with metric listings and land measures.
Limitations to watch for
The tool adds exactly two rectangular areas. Irregular rooms need to be split into rectangles. The waste factor should reflect your project (10% for flooring is typical). The material cost is only as good as the price per unit you enter.
How to use it in practice
Measure each space in feet and enter the dimensions. Add a waste factor when buying materials. Use the conversions for real-estate comparisons or international products.
- Enter the length and width of the first area.
- Optionally enter a second area.
- Enter waste % and price per unit (optional); the tool totals and converts.
How this calculator works
Formula
Area 1 = length1 × width1; Area 2 = length2 × width2; base total = area1 + area2. Total with waste = base × (1 + waste%). Conversions: sq yd = total ÷ 9, sq m = total × 0.09290304, acres = total ÷ 43,560. Estimated material cost = total × price per unit.
Worked example
A 12×10 ft area (120 sq ft) plus an 8×6 ft area (48 sq ft) = 168 sq ft. With 10% waste: 184.8 sq ft ≈ 20.5 sq yd, 17.2 sq m, or 0.0042 acres. At $5/sq ft, materials ≈ $924.
Assumptions to verify
- Up to two rectangular areas are entered.
- Waste is a percentage of the base total.
- Conversions use standard international definitions.
Frequently asked questions
How do I calculate square footage?
Multiply length by width for each space, then add them. A 12×10 ft room is 120 sq ft; two such rooms total 240 sq ft.
How many square feet in a square yard?
9 (3 ft × 3 ft). Flooring is sometimes sold by the square yard.
How many square feet in an acre?
43,560. Divide square feet by 43,560 to get acres — useful for land parcels.
How do I convert square feet to square meters?
Multiply by 0.09290304. 184.8 sq ft ≈ 17.2 sq m.
Why add waste?
Materials like flooring and tile need extra for cuts and mistakes. 10% is standard; diagonal layouts need more.
Does this work for triangular or round rooms?
No — split irregular shapes into rectangles, or use the shape-specific calculator for circles and triangles.
What is the price-per-unit for?
Estimating material cost: total square feet × price per square foot (or per square yard if you enter that unit).
Cite this tool
BoringToolsKit. “Square Footage Calculator.” boringtoolskit.com/square-footage-calculator/ (reviewed 2026-08-25). Free to reference in articles, syllabi, and answer posts with a link.
Privacy: Inputs and results stay in this browser. Any future sponsored recommendation or advertisement will be clearly labeled and kept separate from the calculation.