How To Calculate house square footage? | Easy Calculator

There is a standard to measure the square footage where you need to go as precise as possible for calculation. The first most step is to understand how long and wide your space is.

Identifying the room measurements in length and width precisely, including every corner, will help you measure the entire area correctly.

Below is a guide to calculate the square feet of your house or room. We will start with the room first.

Evaluation of Area And Perimeter

For measuring the area and perimeter of the standard square or rectangular room, you need to know the basic and straightforward formula.

Area = Length * Width (L * W)

Perimeter = (Length) + (Width)

The area is another name of square footage. So, with this, there is a primary method to evaluate a room’s square feet.

House square footage calculator

Bedroom x
Living room x
Bathroom x
Garage x
Kitchen x

Optionally enter the price per square footage $

Please input at least length and width.

Square Footage

Estimated Cost

Primary Method To Evaluate Room Square Feet

Once you got the measurements of the entire room with the length and width of your room, you can move ahead with calculations.

Finding the area of a square or rectangular room, you only need to multiply the length and width, and you will get the square feet of your room space.

Square Footage = Length * Width

Let’s take one example, suppose the distance between the first two walls of your room is 13 feet, and the space between another two walls is 15 feet.

In this case, your length and width would be 15 feet and 13 feet. You multiply both to get the room square feet as a result.

15 ft * 13 ft = 195 square feet

Apart from feet, you can also measure in inches and convert them into feet for calculating the area of the room. But all rooms might not be rectangular and square.

They may be in irregular shapes also. Also, some rooms have closets and tables with sofa sets. Thus, you have to do detailing in measurements of square feet.

Evaluation Of Different Types Of Rooms Square Feet

We have already seen how to calculate the area of the square or rectangle room. Thus, for finding out the measurements of different types of rooms, below is the trick –

Rooms Having Closets and Sofas

Rooms that have closets and Sofas are usually like rectangle rooms having small rectangles add ons. Thus calculate the square footage of every rectangle and add them all together. For instance,

Your closet has 7 feet by 7 feet in length and width, respectively. The sofa measures 8 feet by 3 feet in length and width. So there are two similar sofas in L shape.

And your size and width of a room measure 12 feet by 12 feet. So what do you need to do to calculate the open room space area that is the carpet area?

Square footage will be the sum of the sofa area and closet area, which will then be subtracted from the room area.

Sofa Area = Length of Sofa * Width of Sofa = 8 * 3 = 24 sq. ft

Closet area = Length of Closet * Width of Closet = 7 * 7 = 49 sq. ft

Room Area = Length of Room * Width of Room = 12 * 12 = 144 sq. ft


Sum of Sofa and Closet Area = Area of Sofa + Area of closet = 24 + 49 = 73 sq. ft

Area you get remaining = Area of room – Area of sofa and closet = 144 – 73 = 71 sq. ft

Irregular shaped rooms

When you have the irregular shape of rooms, you need a standard tool for measurement applied to odd-shaped rooms.

You need to divide your room into separate room sections, which are easy to evaluate on their own, and then sum it up to get the results.

If your room has many corners, use the triangle formula – it is just half of a rectangle or square.

So, for irregular shape room, a formula goes –

Square Feet Of Main section = Length * width

Square feet of a small section (1, 2, 3, etc.) = Length * Width

Square footage of the room = Square feet of main section + Square feet of small sections separately.

Let’s take the instance,

The main section of the room is 12 feet by 12 feet, and the other additional area is 6 feet by 5 feet in length and width. For finding the total square footage of an irregular-shaped room, first, calculate areas separately and add them all together.

Area of main section = 12 * 12 = 144 sq ft

Area of small additional section = 6 * 5 = 30 sq. ft

Total square footage of the irregular room = 144 + 30 = 170 sq. ft

So these are some ways to calculate the room area. You can calculate the area of the entire house by evaluating different rooms one by one precisely. For measuring the square feet of the entire house, you need to add areas of different rooms.

  • Living room
  • Kitchen
  • Bathroom
  • Bedrooms
  • Basement
  • Family room
  • Dining room
  • Heating and cooling system space

These add to your home square footage, while there are some that you do not need to add in the total square feet of the house –

  • Attic
  • Garage
  • Separate storage
  • Pool house

These do not add to the general area of the house. You may mention them differently.

Summing It

The above guide will be helpful for you to calculate the room’s square feet correctly one by one to evaluate the total square footage of the house. It will help you choose and buy material accordingly.