Square Footage Calculator
How to calculate square footage
Square footage is a measurement of area, which is the total space occupied by a two-dimensional shape. Calculating square footage depends on the shape you're dealing with. Here are the formulas for common shapes:
Rectangle
For a rectangle, multiply the length by the width:
Area = Length × Width
Triangle
For a triangle, multiply the base by the height and then divide by 2:
Area = (Base × Height) / 2
Circle
For a circle, multiply π (approximately 3.1416) by the radius squared:
Area = π × Radius²
Trapezoid
For a trapezoid, add the two parallel sides (bases), multiply by the height, and then divide by 2:
Area = (Base a + Base b) × Height / 2
Multiple Items
When calculating for multiple identical items, simply multiply the area of one item by the quantity:
Total Area = Single Item Area × Quantity
Unit Conversion
All calculations are first done in square feet, then converted to your selected output unit:
- 1 square foot = 144 square inches
- 1 square foot = 0.092903 square meters
- 1 square foot = 929.0304 square centimeters
- 1 square foot = 0.111111 square yards
Why calculate area?
Area calculations are essential in many construction and real estate applications:
- Determining how much material you need for flooring, roofing, or painting
- Calculating property values and rental prices
- Planning landscaping projects
- Estimating construction costs
- Complying with building codes and zoning regulations
- Calculating material needs for multiple identical items (like tiles, floorboards, etc.)
- Converting between different measurement systems (imperial and metric)
FAQs
To convert between area units, you need to know the conversion factors. For example, to convert square feet to square meters, multiply by 0.092903. This calculator handles all conversions automatically based on your selected output unit.
A 12x12 room has 144 square feet (12 feet × 12 feet = 144 square feet). This equals 20,736 square inches, 13.378 square meters, or 16 square yards.
First calculate the area for one item using the appropriate shape formula, then multiply that area by the number of items you have. For example, if each tile is 1 sq ft and you have 100 tiles, your total area would be 100 sq ft.
For irregular shapes, divide the area into regular shapes (rectangles, triangles, etc.), calculate each area separately, and then sum them all together to get the total area.
Linear feet measure length in one dimension, while square feet measure area in two dimensions. To convert linear feet to square feet, you need a second dimension (like width). For example, a 10 linear foot board that's 1 foot wide covers 10 square feet.