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Last updated: June 1, 2026

Square Footage Calculator: Including Irregular Shapes

Calculate the square footage of any space, including irregular shapes and multi-section rooms. Add rectangular, triangular, and circular sections to get an accurate total for flooring, painting, and material estimates.

Room Sections

Area: 180.0 sq ft

Total Square Footage

Total Area180.0sq ft
Square Yards20.00sq yd
With 10% Waste198.0sq ft
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Understanding the Square Footage Calculator

A square footage calculator finds the area of a space — a room, lot, wall, or irregular shape — which is the starting point for almost every building, flooring, painting, and landscaping project. It also helps with real estate, where price is often quoted per square foot.

Beyond simple rectangles

For a basic rectangle, area is length times width. Real spaces are often L-shaped or irregular, in which case the trick is to break them into rectangles, calculate each, and add them up. For circular or triangular areas, the calculator applies the appropriate geometry so you do not have to remember the formulas.

Why it underpins material estimates

Almost every material calculation — flooring, paint, tile, sod — starts from square footage, so getting it right matters. Measure carefully and double-check, since an error here multiplies through your entire material order. Keep units consistent, and convert between square feet and square meters as needed for your suppliers.

Tips & things to know

  • Break irregular spaces into rectangles and add them up.
  • An error here multiplies through every material estimate.
  • Keep measurement units consistent throughout.

Formulas

Rectangle: Length × Width

Triangle: (Base × Height) ÷ 2

Circle: π × Radius²

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How to Use the Square Footage Calculator

1

Open the Square Footage Calculator

Navigate to the Square Footage Calculator page on Redicalc. The calculator loads instantly with no sign-up required.

2

Enter your values

Fill in project dimensions, material quantities, or specifications. Toggle between metric and imperial units if available.

3

Review your results

Your square footage results appear instantly as you type. Review the breakdown, charts, or detailed analysis provided.

4

Adjust and compare

Try different input values to compare scenarios. This helps you understand how changes affect the outcome.

5

Share or save your results

Use the copy or share buttons to save your results. You can also bookmark the page for quick access later.

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Frequently Asked Questions

How do I measure an L-shaped room?

Divide the L into two rectangles, calculate each area separately (length × width), then add them together.

How do I convert sq ft to sq yards?

Divide square feet by 9. For example, 180 sq ft ÷ 9 = 20 sq yards. This is useful when buying carpet.

Should I include closets in square footage?

For real estate purposes, yes. For flooring, include them if you plan to install flooring in closets. For painting, measure closet walls separately.

How much extra material should I order?

Add 10% for rectangular rooms and 15% for irregular shapes. This accounts for cuts, waste, and mistakes.

What tools do I need to measure square footage?

A tape measure for small rooms, a laser distance measurer for larger spaces. A notepad for sketching the layout is also very helpful.