How to Calculate Square Footage
Knowing how to calculate square footage is an essential skill for home improvement projects, real estate, and construction. Whether you are laying hardwood floors, pouring a concrete patio, or buying paint, you need to know the total area of your space. Our Square Footage Calculator handles the math and unit conversions instantly.
If you are ordering concrete specifically, you will need to convert this area into a volume (Cubic Yards). You can use our Concrete Slab Calculator for that specific task.
The Basic Formula
Finding the area of a square or rectangular room is straightforward. You multiply the Length by the Width.
Area = Length × Width
For example, a bedroom that is 12 feet long and 10 feet wide has a total area of 120 square feet (12 × 10 = 120). To read more about the mathematical definitions of area, check out the Square Foot article on Wikipedia.
Why Add a Wastage Percentage?
If your room is exactly 120 square feet, ordering exactly 120 square feet of flooring is a recipe for disaster. Why? Because materials must be cut to fit edges, corners, and doorways, resulting in unusable scrap pieces.
Contractors universally recommend adding an overage or wastage factor to your order.
- 10% Overage: The standard recommendation for most rooms and basic installations (like laminate or vinyl planks).
- 15% Overage: Recommended for rooms with many angles, bay windows, or if you are installing tile in a complex pattern (like herringbone or diagonal).