📐 Square Footage Calculator

Add a Room or Area

Room Name / Label

Length

feet meters

Width

Keyboard: Type dimensions and press Enter to add. Press Esc to clear all.

Project Totals

What Is Square Footage and Why It Matters

Square footage is a measurement of area, calculated in square feet. It's one of the most important metrics in real estate, construction, and home improvement. For a simple rectangular area, you calculate it by multiplying the length by the width. This single number is crucial for a variety of tasks: from determining the sale value of a property to estimating the amount of materials needed for a renovation. Whether you're buying paint, installing new flooring, or sizing an HVAC system, knowing the precise square footage is the essential first step to getting an accurate and cost-effective result.

How to Calculate Area for Common Shapes

While most rooms are rectangular, you may encounter different shapes. The formulas for area are straightforward:

• Rectangle/Square: This is the most common. The formula is simply: $Area = Length \times Width$.
• Circle: To find the area of a circular space, you need its radius (the distance from the center to the edge). The formula is: $Area = \pi \times radius^2$, where π (Pi) is approximately 3.14159.
• Triangle: For a right-angled triangle, the formula is: $Area = 0.5 \times Base \times Height$. This calculator simplifies the process for any shape you need to measure.

Estimating Materials from Square Footage

Once you have your total square footage, you can confidently estimate the materials required for your project. This prevents over-buying and saves money.

• Flooring: Flooring materials like tiles, laminate, or carpet are sold by the square foot or square meter. Calculate your room's area, then add a **waste factor** (typically 10-15%) to account for cuts, mistakes, and future repairs. For example, for a 180 sq ft room, you should purchase at least 198 sq ft of flooring.
• Paint: To estimate paint, you need the area of the walls, not the floor. You can find this by calculating the room's perimeter (2 × Length + 2 × Width) and multiplying it by the ceiling height. One gallon of paint typically covers 350-400 square feet.
• Trim/Baseboards: This is based on the perimeter of the room (linear feet), not the area.

Measuring Irregular Rooms & Polygons

Not all rooms are perfect squares. To measure an L-shaped room or one with an alcove, the easiest method is to divide the space into smaller, regular rectangles. Measure the length and width of each rectangle, calculate their individual areas, and then add them all together for a total. For even more complex shapes, you can triangulate the area by breaking it into multiple triangles and summing their areas. The key is to transform a complex problem into a series of simple ones.

Frequently Asked Questions

• Do closets count in square footage? Yes, closets are generally included in the total square footage of a room.
• What is the difference between square feet and linear feet? Square feet measure area (a 2D space), while linear feet measure length (a 1D line). You use square feet for flooring and paint, but linear feet for baseboards or trim.
• How do I handle angled walls? For a room with an angled wall, you can typically break the room into a rectangle and a triangle, calculate each area separately, and add them together.
• Should I include the space under cabinets? For flooring estimates, yes. You should calculate the total floor area of the room before cabinets are installed to ensure you have enough material.

Measure carefully — verify on site before ordering materials.