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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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.

Related calculators

Square Footage Calculator (Rectangular)
Length × width = ft². The simplest area calc.
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Two-rectangle L-shaped area = (L1×W1) + (L2×W2).
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L × W = floor area in ft². For flooring orders, multiply by 1.10 (10% waste).
Lawn Square Footage Calculator
L × W = lawn area. For seed, sod, fertilizer orders.
Patio Square Footage Calculator
L × W = patio area. For paver/concrete orders.
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Fill PDF Form
PDF

Pre-fill a fillable PDF form (AcroForm) — type one line per field as `name=value`. Output is a filled PDF you can sign or print.