Measure length and width
Measure the two sides of each rectangular section. HomeMeasureWorks can accept imperial or metric measurements and converts the units automatically.
Area = length × width
Measurement tools
Square Footage Calculator
Calculate the total area of one or more spaces and subtract sections you do not want included.
Calculation method
How to calculate square footage
Square footage measures the area of a surface. For a rectangular room or section, multiply its length by its width. If your project contains several sections, calculate each one and add them together. Spaces you do not want included can then be subtracted from the measured total.
Add multiple areas
If the room or project is made from several rectangular sections, calculate each section separately and add their areas together.
Measured area = Area 1 + Area 2 + ...
Subtract excluded spaces
Use excluded areas for rectangular sections that should not count toward the final project area, such as an opening or another untiled or uncovered space.
Net area = measured area − excluded area
Convert the result
The calculator reports the final area in square feet, square meters, and square yards so you can use the same measurement with different project specifications.
1 yd² = 9 ft²
Worked example
Suppose the main room measures 10 × 20 ft. Its area is 200 ft².
You then add a second section measuring 5 × 10 ft, which contributes another 50 ft². The total measured area is therefore 250 ft².
If a 2 × 5 ft section should be excluded, subtract its 10 ft² area:
250 ft² − 10 ft² = 240 ft²
The final project area is therefore 240 ft², which is approximately 22.30 m² or 26.67 yd².
How to measure an irregular room
Many rooms are not perfect rectangles. For an L-shaped room or another layout that can be divided into simple sections, split the space into separate rectangles and use Add another area for each section.
For example, instead of trying to measure an entire L-shape at once, divide it into two rectangles, enter both sets of dimensions, and let the calculator add their areas.
Use Subtract a space when a rectangular section lies inside your measured area but should not be included in the final total.
Square feet, square meters, and square yards
Area units describe two-dimensional surface size. They should not be confused with ordinary length units such as feet, meters, or yards.
Square feet to square meters1 ft² = 0.09290304 m²
Square yards to square feet1 yd² = 9 ft²
Square meters to square feet1 m² ≈ 10.7639 ft²
You do not need to perform these conversions manually. HomeMeasureWorks converts the calculated area and displays all three results together.
Where square footage is useful
A reliable area measurement is the starting point for many home projects. Square footage can be used when planning flooring, tile, paint coverage, carpeting, landscaping, insulation, and other material estimates.
The square footage result itself does not include material waste, package sizes, coverage rates, or product pricing. Those factors belong to the specialized material calculator for the project you are planning.
What this estimate assumes
- The dimensions entered into the calculator are accurate.
- Each entered section is treated as a rectangle.
- Added areas do not unintentionally overlap one another.
- Excluded spaces are contained within the measured project area.
- Unit conversions use the measurements entered in the calculator rather than rounded display values.
For best results: measure each section carefully and verify important project dimensions before purchasing materials or ordering work.