Irregular Square Footage Calculator

Sum of rectangles. Enter length×width pairs (one per line).

Inputs

Each line: length space width.

Result

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General calculation reads

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How to use this calculator

  • Decompose your floor plan into rectangles.
  • Enter each as "L W" on a separate line.
  • Read the sum.

About this calculator

For complex shapes that aren't simple rectangles, decompose into a sum of rectangles. Walk the floor plan, measure each rectangle separately, and sum. The calculator parses any number of L×W pairs.

Frequently asked

How to decompose a complex shape?+
Pick the largest rectangle that fits, then add/subtract smaller pieces. Or split along structural lines (interior walls).
What about curved sections?+
Approximate as rectangles or treat as polygons (use shoelace formula). Curved areas often within 1-2% by rectangular approximation.
Subtract a "negative" rectangle?+
Not directly supported. Compute and subtract manually, or split positive areas to avoid the negative.
Maximum sections?+
Practical limit ~50. The calculator handles any number, but the breakdown shows only first 8.
Conversions?+
See square-footage-rectangular FAQs.

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