How to Calculate Square Footage

How to calculate square feet

To calculate an area in square feet, you will need measurements for the width and length (for a square shape) or the diameter (for a circular area). It may be that the area you're looking to measure is a strange shape (such as a room or garden). In this case, dividing it up into smaller parts and doing individual calculations is a good way to calculate the overall square footage.

Let's say you have a rectangular-shaped room and you want to calculate the square footage area for flooring or carpet. The easiest method for calculating the square footage is to measure the length and width in feet and then multiply the two figures together to give you a result in ft2. If you're measuring a room for flooring, take a look at our article on how to measure for a new floor.

Should you find yourself needing to calculate an area of square feet in an 'L' shape, consider dividing the shape up into rectangular sections and treating them as separate areas for calculation (adding them together at the end). For more instructions, see our full article: how to calculate square footage.

How to calculate square footage?

Measure the length in feet, Measure the width in feet. Multiply the length figure by the width figure.  This will be your total square footage for that portion of your project.  Continue to repeat this for all parts of the space that will get the same tile.   Add these together for your total square footage.

Measuring in inches works as well.  Do the math the same way, then divide by 144 to get your total in square feet. When calculating square footage account for the entire space (i.e. under vanity/cabinets).

Calculating Square Footage of Materials: How Much Should You Adjust for Waste?

After you cut tiles, wallpaper or other materials you may have odd pieces left over that you cannot use. You need to order enough material to account for some waste to ensure you have enough to finish the project. Also, it makes sense to pad your estimate to cover any mistakes that occur.

A general rule of thumb is to order 5% to 10% more material than the square footage of your space. If you end up with a lot of extra material at the end of your project, you can keep some in case repairs are needed down the road. Most stores will also accept returns of unopened material.

Methods for how to calculate square feet for different shapes

Different shapes have different ways of calculating square footage. For all the shapes, it may be helpful to convert the measurement of the shape into square feet before making your calculation. Converting the measurements can help you keep the shape to scale, especially if the sides have different measurements, such as feet and inches or yards and meters. You could also perform the calculation and then convert the final measurement to square feet to achieve the same result.

Use the methods below to help you calculate square feet for seven different shapes:

How to calculate square feet for squares and rectangles

Squares and rectangles use the same formula to calculate square feet. This formula is:

A = length x width

In this equation, "A" is the total area of the shape in square feet. The length is the measurement of one side of the shape in feet and the width is the measurement of another side of the shape in feet. You can use the steps below to calculate the square footage of squares and rectangles with the formula above:

1. If necessary, convert your measurements for each side of the shape into feet.

2. Multiply the length and the width of the shape together to get the area of the square or rectangle in square feet.

How to calculate square feet for triangles

The square footage formula for triangles is:

A = 1/2 base x height

In this equation, "A" is the area of the triangle in square feet, "1/2 base" is the length of the bottom side of the triangle in feet and the height is the vertical distance from the bottom side of the triangle to the top corner in feet. You can use the following steps to calculate the area of a triangle:

1. Convert the measurements for the base and height into feet.

2. Divide the length of the base by two to get half of the base.

3. Multiply half the base by the height to find the square footage area of the triangle.

How to calculate square feet for circles

To calculate the area of a circle, it's necessary to use the number pi, which is represented by the symbol π. You can use the decimal 3.14 to represent the value of pi. The formula to calculate the square footage of a circle is:

In this equation, "A" is the total square footage, π is equal to 3.14 and the radius is the distance from the exact center of the circle to the outside edge in feet. To calculate the area of a circle, use the following steps:

1. If it isn't already in feet, convert the measurement for the radius into feet.

2. Multiply the length of the radius by itself to get feet squared.

3. Once you've calculated the square feet of the radius, multiply that result by pi to get the total area of the circle in square feet.

How to calculate square feet for trapezoids

To calculate the square footage of a trapezoid, you can use the formula:

A = [(base length + top length) / 2] x height

In this equation, "A" is the total area of the shape in square feet. The base length is the length of the bottom of the trapezoid in feet, and the top length is the length of the top of the trapezoid in feet. The height is the vertical distance from the base length to the top length of the trapezoid in feet. You can use the following steps to calculate the area of a trapezoid:

1. If necessary, convert the measurements for the base length, top length and height into feet.

2. Add the base length and the top length together to calculate the area for the nonrectangular sections of the trapezoid created by the diagonal sides.

3. Divide the sum of the base length and the top length by two to ensure you account for the diagonal sides in the equation.

4. Multiply that result by the height to find the area of the trapezoid in square feet.

How to calculate square feet for rhombuses

To calculate the square footage of a rhombus, you can use the following formula:

A = distance from one pair of opposite angles x distance from the other pair of opposite angles

In this equation, "A" is the area of the rhombus in square feet and the distances from both pairs of opposite angles are in feet. You can calculate the area of a rhombus using the following steps:

1. Convert the measurements for the distances of the rhombus into feet if necessary.

2. Multiply the interior lengths, which are the distances from opposite angles within the rhombus, to find the area in square feet. The interior lengths intersect with each other at the center of the shape.

How to calculate square feet for parallelograms

To calculate the square footage of a parallelogram, you can use the formula below:

A = base x height

In this equation, "A" is the area of the parallelogram in square feet, the base is the length of the bottom side of the parallelogram in feet and the height is the vertical distance from the base of the parallelogram to the top side in feet. You can calculate the square footage of a parallelogram using the steps below:

1. If necessary, convert the measurements for the base and height into feet.

2. Multiply the base by the height of the parallelogram to find its area in square feet.

What to leave out

A good rule of thumb to ensure you’re taking proper measurements is to exclude space you can’t walk on or live in. These types of spaces do not count as “gross living area.”

“Someone might think, ‘If I get the measurement of my first floor and I have a two-story house, I just multiply that by two,’” Day says. However, if that first floor includes a two-story foyer, you can’t count the non-usable space.

Basements and garages, even if they are finished, don’t generally count toward total square footage. Basements are typically excluded because they are built below grade, meaning below ground level. If your state does allow basements to be included in the total square footage of a home, though, you’ll likely need an ingress and egress, or a safe way to enter and exit the basement to the outside.

Finished attic spaces — with some regulations, including ceiling heights — can count toward the total square footage of your home. If you are planning to sell your home, work with a real estate agent to craft a listing that accurately reflects your property.

How many square feet is a 12×12 room?

The square footage of a room measuring 12 feet wide by 12 feet long is 144 square feet. To calculate this you simply multiply the width by the height. 12ft × 12ft = 144 sq ft.

Convert among square inch, square foot, square yard and square meter

You could, for example, perform all of your measurements in inches or centimeters, calculate area in square inches or square centimeters then convert your final answer to the unit you need such as square feet or square meters.

To convert among square feet, yards and meters use the following conversion factors.  For other units use our calculator for area conversions.

• Square Feet to Square Inches
• multiply ft2 by 144 to get in2
• Square Feet to Square Yards
• multiply ft2 by 0.11111 to get yd2
• Square Feet to Square Meters
• multiply ft2 by 0.092903 to get m2
• Square Yards to Square Feet
• multiply yd2 by 9 to get ft2
• Square Yards to Square Meters
• multiply yd2 by 0.836127 to get m2
• Square Meters to Square Inches
• multiply m2 by 1,550 to get in2
• Square Meters to Square Feet
• multiply m2 by 10.7639 to get ft2
• Square Meters to Square Yards
• multiply m2 by 1.19599 to get yd2

How Do You Calculate Square Footage?

All home projects — from wallpapering to landscaping — start with proper measurements. To find the square footage of a space, you’ll need a measuring tape and a method of recording your measurements. Here are the steps:

1. Start with the longest side of the room or space and measure the length. Be sure your tape measure is in a straight line.
2. Write down the length in feet.
3. Repeat the process on the shortest side of the room or space you are measuring. For square spaces, all four sides will be the same.
4. Write down the width in feet.
5. Multiply the two values together to get square feet.

Measuring for Schluter Profile Edging

Measure the length of any outside edge where your tile edge would be exposed.    Not all edging is the same.  Speak to your design associate about different uses.