Square Footage Calculator
Square footage is just length times width, but it underlies a surprising amount of everyday planning: flooring, carpet, tiling, turf, rent per square foot, and the size of a room you are describing to someone. This calculator finds the area of a rectangular space in both square feet and square yards from two measurements. It is deliberately the plain-arithmetic version — for materials, depth, and waste allowances, the construction calculators take the area further into bags, gallons, and tonnes.
Calculate
Default result: 120.00
Square Footage Calculator · Result
calculators.dev
Area (square feet)
12 × 10
- Area (square yards)
- 13.33
Reviewed by the calculators.dev team · Last updated 2026-06-23
How to calculate
Measure the length and width of the space in feet and enter them. The calculator multiplies the two to get the area in square feet, then divides by nine to also show square yards, since a square yard is a three-by-three-foot square. A 12-by-10-foot room works out to 120 square feet, or about 13.33 square yards. For an L-shaped or irregular space, split it into rectangles, find each area here, and add them together. The result updates as you type.
area = length × width, with both sides in the same unit so the result is in square units. To convert square feet to square yards, divide by 9 (because 1 yard = 3 feet, so 1 square yard = 3 × 3 = 9 square feet). This is the area of a rectangle only; circles, triangles, and irregular shapes use their own area formulas.
Example calculation
A rectangular room 12 feet long and 10 feet wide covers 12 × 10 = 120 square feet. Because a square yard is 3 feet by 3 feet, or 9 square feet, dividing 120 by 9 gives about 13.33 square yards — the figure flooring sold by the yard uses. The area is simply the two sides multiplied together.
- squareFeet
- 120
- squareYards
- 13.33
Assumptions
- The space is rectangular; divide an irregular area into rectangles and sum their square footage.
- Both measurements are in feet, so the area comes out in square feet (and square yards after dividing by 9).
- This is pure floor area — it does not add a waste allowance or convert to material quantities, which the construction calculators handle.
Common mistakes
- Mixing units, such as entering length in feet and width in inches, which makes the area wildly wrong — convert to one unit first.
- Treating an irregular room as a single rectangle instead of splitting it into parts and adding the areas.
- Confusing square feet with linear feet; area multiplies two measurements, while a perimeter adds the sides.
Frequently asked questions
How do I calculate square footage?
Multiply the length by the width when both are in feet. A 12-by-10-foot room is 12 × 10 = 120 square feet.
How many square feet are in a square yard?
Nine. A square yard is a three-by-three-foot square, so divide square feet by 9 to get square yards.
How do I find the area of an L-shaped room?
Split it into rectangles, calculate each rectangle's square footage separately, and add the results together.
Does this account for flooring waste?
No — it gives the exact floor area. Flooring is usually bought with about 5–10% extra for cuts and offcuts, which the material calculators include.