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How to calculate floor plan?

To calculate square footage from a floor plan, follow four steps. First, establish the scale. Scaled drawings state it directly (like 1/4" = 1'), while marketing plans require calibrating against a known dimension such as a labeled wall length. Second, break the plan into simple shapes: rectangles, triangles, and circles. Third, calculate each shape's area (length x width for rectangles) and add them together. Fourth, subtract any openings or excluded spaces like stairwells on upper floors, depending on the standard you're following.

For gross living area under ANSI Z765, measure to the exterior walls and exclude garages and unfinished areas.

Doing this by hand with a ruler and calculator works but is slow and error-prone, especially with angled walls or curved features. MeasureFloorPlan automates the whole process: upload the plan, set the scale once, trace each room or the full perimeter, and get exact areas instantly, including irregular shapes that don't decompose neatly into rectangles. It's the same math, done faster and without arithmetic mistakes.