Rectangle
Area = length × width
Multiple mode totals each rectangle multiplied by its quantity.
Area formulas
How square footage is calculated.
Every dimension converts to one canonical unit before the selected geometry formula is applied. Rectangular cutouts are subtracted afterward.
Circle
Area = π × (diameter ÷ 2)²
Measure the complete diameter through the center.
Triangle
Area = base × perpendicular height ÷ 2
The height must meet the chosen base at a right angle.
Trapezoid
Area = (side A + side B) ÷ 2 × perpendicular height
Side A and side B are the parallel sides.
Net area
Net area = gross area − rectangular cutouts
Cutouts must total less than the gross area.
Use the result
From geometric area to project planning.
L-shapes and complex areas
Break the outline into non-overlapping rectangles, enter each section in Multiple rectangular areas, then add any cutouts.
Cutouts
Subtract only rectangular areas that should not count toward the project surface. Leave cutouts empty when the whole shape is included.
Square feet, yards, and meters
The same net physical area is displayed in the primary unit system plus useful square-yard, square-foot, or square-meter equivalents.
Material quantities
Square footage is only the measured area. Use a specialized calculator to apply product coverage, allowances, packaging, or material-specific formulas.
Need a material quantity?
Continue with a specialized calculator when the project needs coverage, packaging, depth, or purchase rounding.
Scope and limits
A geometric project-area calculator
- Shapes and rectangular sections are regular, measured in the same plane, and do not overlap.
- Triangle and trapezoid heights are perpendicular to their stated bases or parallel sides.
- Cutouts are rectangular and their combined area is smaller than the gross shape.
- No waste allowance, material coverage, cost, or price per square foot is included.
- This calculator measures geometric project area. It does not determine reportable living area for real-estate listings, appraisals, tax records or building-code purposes.
Square footage questions
Frequently asked questions
How do I calculate square footage?
For a rectangle, multiply length by width. Choose the matching mode for circles, triangles, or trapezoids, and use Multiple rectangular areas for a divided project.
How do I calculate an L-shaped area?
Divide the L-shape into non-overlapping rectangles and enter them in Multiple rectangular areas. Add their areas rather than using a special L-shape shortcut.
Can I subtract openings or uncovered areas?
Yes. Add rectangular cutouts with their dimensions and quantity. Their combined area must remain smaller than gross area.
How many square feet are in a square yard?
One square yard equals exactly 9 square feet.
Does this calculate material quantities?
No. It calculates geometric area only. Use the appropriate Concrete, Paint, Tile, Flooring, Drywall, Paver, or other specialized calculator for material-specific planning.
Can I use this as reportable living area?
No. This calculator does not apply real-estate, appraisal, tax-record, or building-code measurement standards.
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Keep planning your project.
Use another Measivo calculator to estimate the next material on your list.