Square Footage Calculator

Calculate total area for rooms, walls, floors, patios, yards, and material takeoffs. Add multiple shapes, convert units, and include waste without uploading measurements.

Project areas

Use one row per room, wall, zone, or shape. The calculator totals all valid rows.

Results

Total with waste
0 ft²
Enter measurements and calculate to see totals.
Base area0 ft²
Waste added0 ft²
Square meters0 m²
Square yards0 yd²

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Square footage formulas

This tool converts each input to feet first, then computes area. The core formulas are:

  • Rectangle: area = length x width
  • Circle: area = pi x (diameter / 2)^2
  • Triangle: area = base x height / 2
  • Waste-adjusted total: total = base area x (1 + waste% / 100)

Assumption: measurements describe flat plan area. For sloped roofs, stairs, irregular curves, or rooms with many openings, split the project into smaller measured sections and verify onsite.

For ordering materials, treat the calculated square footage as the measured coverage area before packaging rules. Flooring cartons, tile boxes, rolls, and sheet goods often require rounding up to whole packages after waste is applied. If a product has directional grain, pattern repeat, minimum seam length, or required overlap, add that allowance separately or use a dedicated coverage calculator for the material.

How to measure accurately

  1. Sketch the project and split irregular spaces into rectangles, circles, triangles, or known custom areas.
  2. Measure to the finished boundaries you plan to cover. For walls, enter wall width and height as a rectangle.
  3. Enter each section as a separate row so you can check the line-item totals before ordering material.
  4. Add waste for cuts and mistakes: 5% for simple layouts, 10% for most flooring and tile, and 15% or more for diagonal, patterned, or complex spaces.

Square footage FAQs

What is the difference between square feet and linear feet?

Square feet measure area: length times width. Linear feet measure one dimension, such as trim, baseboard, or edging length.

Can I subtract doors, windows, or cabinets?

Not as a negative row. Enter net dimensions, split the space around the opening, or leave small openings in the estimate as a waste buffer when that matches your material-ordering practice.

Why does the calculator show square meters and square yards?

Suppliers may price material by ft², m², yd², square, roll, carton, or pallet. Showing conversions helps you compare quotes and product labels.

Is this a structural or code-compliance calculator?

No. It estimates flat area only. It does not check structure, load, fire rating, waterproofing, or building-code requirements.

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