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
Area in Square Feet:
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. One square foot is equal to a square area with a length and width of 12 inches.
You can calculate the square feet of a space using the area formula, which states that the area is equal to the length times the width. This is the formula for a rectangle, but we’ll cover the area formulas for different shapes below.
Before you multiply the length and width together, make sure each measurement is in feet.
To calculate the square footage using measurements in inches or another measurement, 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 for different shapes.
How to Convert to Square Feet
You can also calculate square feet by converting a known area that’s in different units of measure. You can convert square inches, square yards, or metric units such as square meters to square feet using one of the formulas below.
sq ft = sq in ÷ 144
sq ft = sq yds × 9
sq ft = sq m × 10.764
You can use an area converter to convert any area measurement to sq ft.
How to Calculate the Square Feet of a Home or Residence
As noted above, measuring the square footage of a house is important in real estate and for common improvements. Unlike measurements for a flooring project, when you’re measuring the area of a home or residence for real estate purposes, some special considerations apply to determine the inhabitable square footage.
Since the livable size of a home determines the market value, appraisal price, and property taxes, getting an accurate measurement is important.
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 like bedrooms and closets count toward the square footage of a home, while outdoor spaces such as the garage 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 (GLA) of a home.
To calculate the total area of a home, measure each room in feet using a tape measure. Then, for each room, multiply the length of the room by the width to get the square footage.
For oddly shaped rooms, split the room into smaller, easily measurable sections, and calculate the area of each section.
Finally, add the area measurements together to find the total square foot value. The calculator above can help find the square feet of one room or multiple rooms using this method.
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