Square Footage Calculator - Multiple Shapes & Areas

How to Calculate Square Footage

Square footage is a measurement of area, essentially how much two-dimensional space a given surface covers. Whether you're laying new flooring, buying paint, or planning a garden, calculating accurate square footage is a critical first step.

To find the square footage of a basic rectangular space, simply measure the length and width of the area in feet and multiply those two numbers together. For example, a room that is 10 feet wide and 12 feet long has an area of 120 square feet (10 x 12 = 120).

Measuring Different Shapes

Not every room or project area is a perfect rectangle. You may need to measure circular spaces or triangular sections to get an accurate total.

• Rectangles: Length × Width. The most common shape for rooms and outdoor decks.
• Triangles: (Base × Height) ÷ 2. Useful for sloped ceilings, odd-shaped garden beds, or bay windows.
• Circles: π × Radius². Used for circular patios, pools, or unique architectural features. Find the center, measure to the edge (the radius), and square that number before multiplying by Pi (3.14159...).

Complex Areas

When dealing with complex spaces, the easiest method is to break the floor plan down into smaller, standard shapes. Calculate the square footage of each individual rectangle, triangle, or circle separately, and then add them all together to find your total area. Our calculator allows you to add multiple sections at once so you can compute the entire project in one place without having to remember individual measurements.