Square Footage Calculator Formula

Understand the math behind the square footage calculator. Each variable explained with a worked example.

Use the Square Footage Calculator

Formulas Used

Square Footage

sqft = total_length * total_width

Square Meters

sqm = sqft * 0.0929

Acres

acres = sqft / 43560

Variables

VariableDescriptionDefault
length_ftLength (feet)(ft)15
length_inLength (inches)(in)0
width_ftWidth (feet)(ft)12
width_inWidth (inches)(in)0
total_lengthDerived value= length_ft + length_in / 12calculated
total_widthDerived value= width_ft + width_in / 12calculated

How It Works

Square Footage Formula

Area = Length × Width

Conversions

  • 1 sq ft = 0.0929 sq meters
  • 1 acre = 43,560 sq ft
  • 1 sq yard = 9 sq ft

    • Worked Example

    A room that is 15 ft × 12 ft.

    length_ft = 15length_in = 0width_ft = 12width_in = 0
    1. 01Area = 15 × 12 = 180 sq ft
    2. 02In square meters = 180 × 0.0929 = 16.7 sq m

    Ready to run the numbers?

    Open Square Footage Calculator