Square Footage Calculator

Our square footage calculator enables you to calculate the square footage of a space so that you can get an accurate idea of your landscaping, tilling, drywalling, framing, flooring and painting needs. The calculator will also give you an estimate of your likely expenses for the materials you will need.

You can calculate the square footage of a range of shapes, specifically, sector, rectangle, ellipse, annulus, rhombus, trapezoid, rectangle border and triangle.

To calculate the square footage of your space, choose the shape of the area and fill in the values required in imperial measurements. Finally, click on "Calculate".

Square Footage Calculator

Formulas

The term 'square footage' denotes an area of measurement, with 'square feet' denoting a unit of area. Our square footage calculator applies the formulas below to determine the square footage of various shapes:

  • Square: Area (ft2) = Side Length2
  • Rectangle: Area (ft2) = Length × Width
  • Rectangle Border: Area (ft2) = [(Inner Length + (2 × Border Width)) × (Inner Width + (2 × Border Width))] - (Inner Length × Inner Width)
  • Circle: Area (ft2) = Pi × Radius 2
  • Trapezoid: Area (ft2) = ((a + b) / 2 ) × h
  • Triangle: Area (ft2) = (1/4) × [ (a + b + c) × (b + c - a) × (c + a - b) × (a + b - c) ] 0.5
  • Annulus: Area (ft2) = Pi × [(Outer Diameter / 2) 2 - (Inner Diameter / 2) 2]
  • Ellipse: Area (ft2) = Pi × r × R
  • Rhombus: Area (ft2) = Base × Altitude
  • Sector: Area (ft2) = Pi × R2 × (θ / 360°)
  • Where Pi = 3.141592654

You may also be interested in our Board Foot Calculator

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