Square Footage Calculator
Find the square footage of an area by selecting a shape and entering the dimensions. Include the price per sq ft to estimate the total cost.
Rectangle Square Footage
Square Square Footage
Border Square Footage
Trapezoid Square Footage
Parallelogram Square Footage
Rhombus Square Footage
Triangle Square Footage
Circle Square Footage
Ellipse Square Footage
Sector Square Footage
Segment Square Footage
Pentagon Square Footage
Hexagon Square Footage
Octagon Square Footage
Regular Polygon Square Footage
On this page:
How to Calculate Square Footage
Square footage is just an area, measured in feet, and it’s often abbreviated sq ft or ft2. It’s often used for construction, home remodeling, and renovation projects such as carpeting, hardwood flooring, tiling, drywalling, painting, and gardening material estimates.
You might be wondering how to calculate square footage. You can find square feet of a space just like you would find the area of a shape; by multiplying the length times the width.
Before multiplying the length and width together, convert all measurements to feet.
To calculate the square footage when measurements are in inches or another unit of measure, first convert the length and width measurements to feet, then multiply them together.
Steps to Calculate Square Feet
Find the area of a room or space in square feet by following these easy steps:
- Measure the length and width of the area.
- Convert these measurements to feet if they aren’t already. Convert inches, yards, or meters to feet using a converter if needed.
- Multiply the length in feet times the width in feet (length × width). Use one of the formulas below to calculate square footage for various shapes.
- To estimate the cost of materials, multiply the total square footage by the price per square foot.
- If the area is not a simple shape, break it into manageable parts and calculate the area of each part separately and then add them together. For example, to measure a floor of your home, calculate the square feet of each room, then add all area measurements together to derive the total square footage.
For example, let’s find the square feet of a room that is 12′ wide by 16′ long.
area = 12′ × 16′
area = 192 sq ft
Square Footage Formulas
Use the formulas below to find the square footage for various shapes. Convert all measurements to feet before using the formulas.
sq ft = l × w
l = length
w = width
sq ft = (l – (2 × b)) × (w – (2 × b))
l = outer length
w = outer width
b = border width
sq ft = πr2
r = radius
π = 3.14159265359
If you know the diameter of the circle, you can find the radius by dividing the diameter in half.
s = 1/2(a + b + c)
sq ft = s(s – a)(s – b)(s – c)
a = edge a
b = edge b
c = edge c
Our area calculator has even more formulas.
How to Convert to Square Feet
You can also convert an area from square inches, square yards, or square meters into square feet. You can use an area converter or one of the formulas below to convert an area measurement into a square footage measurement.
sq ft = sq in ÷ 144
sq ft = sq yds × 9
sq ft = sq m × 10.764
How to Calculate the Square Feet of a Home or Residence
When measuring the square footage of a home or residence, some special considerations apply to determine the inhabitable square footage. The livable size of a home helps determine the market value and price and helps buyers understand the overall size.
Only livable rooms, with finished walls, floor, and ceiling, count toward the finished area of the home. For a room to be considered livable, the space should be finished and should have heating or air conditioning as applicable.
Indoor spaces count toward the square footage of a home, while outdoor spaces typically do not. In fact, the American National Standards Institute has defined rules for what counts as finished area and which rooms contribute to the gross living area of a home.
To calculate the total area, measure each room in feet using a tape measure. Then, multiply the length and width of each room to get the square footage, then add them all together.
The calculator above can help determine the square feet of each room, then simply add all the room’s areas together. We also have great resources on how to measure rooms and complex spaces.
How to Calculate Price per Sq Ft
To calculate the price per square foot of your home, divide the total price by the number of square feet.
price per ft2 = total price ÷ total ft2
For example, to find the price per ft2 of a home that costs $200,000 and is 2,000 ft2 use this formula.
price per ft2 = $200,000 ÷ 2,000 ft2
price per ft2 = $100
If you’d prefer not to do the math, you can also use our unit price calculator to calculate the price per square foot.
- American National Standards Institute, Square Footage — Method for Calculating, ANSI, Z765-2021, approved March 2021,
- Fannie Mae, Standardized Property Measuring Guidelines, December 2021, https://singlefamily.fanniemae.com/media/30266/display