Square Footage Calculator – Guide & Formulas
Calculate the total square footage of a room, house, or plot of land. Supports rectangular, circular, triangular, and irregular spaces.
Easily calculate the total square footage (sq ft) of any space. Ideal for home renovation, flooring, painting, roofing, or land measuring. Supports rectangular, triangular, and circular layouts.
Key Takeaway
Use the free Square Footage Calculator to calculate the total square footage of a room, house, or plot of land. supports rectangular, circular, triangular, and irregular spaces. Get instant results with step-by-step explanations.
How to Use the Square Footage Calculator
- Choose the shape of your space (Rectangle, Triangle, Circle, or Multi-room).
- Input the dimensions in feet, inches, yards, meters, or centimeters.
- Add a waste margin percentage if buying flooring or tiles to ensure adequate coverage.
The Formula
Variable Definitions
- A: Total area in square feet
- L: Length in feet
- W: Width in feet
- r: Radius of circular space
Calculating Flooring for a Dining Room
Find the square footage of a rectangular room that is 12 feet long and 15 feet wide, with a 10% waste allowance.
- Step 1: Identify dimensions: Length = 12 ft, Width = 15 ft.
- Step 2: Calculate base square footage: 12 × 15 = 180 sq ft.
- Step 3: Calculate waste allowance: 10% of 180 = 18 sq ft.
- Step 4: Sum the values: 180 + 18 = 198 sq ft needed.
Frequently Asked Questions
How do I calculate square footage if my measurements are in inches?
Multiply the length in inches by the width in inches to get square inches, then divide by 144 (since 1 sq ft = 144 sq in) to get square footage.
Why should I include a waste factor?
When installing flooring, tiles, or wallpaper, cuts and mistakes occur. A standard waste factor of 5% to 15% ensures you do not run out of material.
How do I calculate square footage of an irregular room?
Break the room down into smaller rectangles, triangles, or semi-circles, calculate the square footage of each part separately, and sum them together.