Gross Floor Area Calculator

Calculate the Gross Floor Area (GFA) of a building by inputting the dimensions of each floor. GFA is the total area of all floors in a building, measured from the exterior shell to the interior face of exterior walls.

Input Parameters

Floor 1

Calculation Results

Calculation Formula

Gross Floor Area (GFA) = Σ(Length × Width) for all floors

Where:
- Length is the measurement of a floor's length in meters
- Width is the measurement of a floor's width in meters
- Σ represents the sum of all floor areas

Gross Floor Area Calculator Calculator Usage Guide

Learn how to use the Gross Floor Area Calculator calculator and its working principles

How to Use the Calculator

  1. Start by entering the dimensions (length and width in meters) for the first floor of your building.
  2. If your building has multiple floors, click the "Add Another Floor" button to add more floor dimensions.
  3. For each floor, enter the length and width in meters.
  4. Click the "Calculate" button to compute the total Gross Floor Area (GFA).
  5. The results will show the area of each individual floor and the total GFA for all floors.

Understanding Gross Floor Area (GFA)

Gross Floor Area (GFA), also known as Gross Building Area (GBA), is a measure of the total floor area of a building, including all habitable spaces. It's calculated by adding up the areas of all floors from the exterior shell to the interior face of exterior walls.

The formula used in this calculator is:

GFA = Floor 1 Area + Floor 2 Area + ... + Floor N Area

GFA = (Length₁ × Width₁) + (Length₂ × Width₂) + ... + (LengthN × WidthN)

Applications of GFA

  • Real estate valuation and pricing
  • Building permits and zoning compliance
  • Leasing calculations for commercial spaces
  • Architectural and engineering design
  • Building code requirements

Important Notes

For accuracy, ensure that:

  • Dimensions are measured in the same unit (meters in this calculator)
  • Only habitable, enclosed spaces are included in the calculation
  • Measurements are taken from the exterior shell to the interior face of exterior walls
  • Basements or below-grade spaces are typically excluded unless they are habitable