Room Area
Floor area of a rectangular room.
Formula
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Example
12 ft × 10 ft = 120 ft²
How it works
A rectangular room has two perpendicular sides: its length and its width. To find the floor area, you multiply those two measurements because the floor can be thought of as made of equal square units arranged in rows and columns. This gives the number of square units needed to cover the entire surface.
When to use it
Use this formula when you need the size of a rectangular floor, such as for carpeting, tile, paint coverage on a floor, or estimating how much space a room has. It is best for rooms with straight sides and right angles.
Worked example, step by step
Length = 15 ft Width = 8 ft A = l × w A = 15 × 8 A = 120 Final answer: 120 ft²
Common mistakes to avoid
- Adding the length and width instead of multiplying them
- Forgetting to use square units like ft² or m²
- Using the formula for non-rectangular rooms without adjusting for the shape
Did You Know?
Measure twice, cut once.
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