Figuring out the square footage of a wall or room is a common calculation that comes up frequently when measuring spaces for flooring, painting, wallpaper, etc. While it may seem complicated, it’s actually quite simple to figure out once you know the basic formula.
Quick Answer
A 12×12 wall has 144 square feet.
To get this, you simply multiply the length by the width:
12 x 12 = 144 square feet
The Formula
Calculating square footage for a wall, floor, ceiling or any rectangular area can be done by using this simple formula:
Length x Width = Area (in square feet or square meters)
So for a 12×12 wall:
12 feet x 12 feet = 144 square feet
Step-by-Step Calculation
Let’s break this down step-by-step:
- Measure the length and width of the wall. For this example, the length is 12 feet and the width is 12 feet.
- Multiply the length by the width:
- Length = 12 feet
- Width = 12 feet
- 12 x 12 = 144
- The result (144) is the total area in square feet.
Since we are multiplying feet by feet, the result is in square feet.
Converting to Square Meters
If you need to calculate the area in square meters instead of square feet, you’ll need to convert the measurements first using the conversions:
1 foot = 0.3048 meters
1 meter = 3.281 feet
So for a 12×12 foot wall:
- Convert 12 feet to meters:
- 12 feet x 0.3048 = 3.66 meters
- Convert 12 feet to meters:
- 12 feet x 0.3048 = 3.66 meters
- Multiply the length and width in meters:
- Length = 3.66 meters
- Width = 3.66 meters
- 3.66 x 3.66 = 13.4556
- Round to 2 decimal places = 13.46 square meters
Accounting for Thickness of Wall
The above calculations give you the surface area of the wall, assuming it has no thickness. However, if you need to account for the thickness of the wall itself, such as for painting or wallpaper, you’ll need to factor that in.
For example, if the wall is 5 inches thick, you would calculate it like this:
- Length = 12 feet
- Height = 12 feet
- Thickness = 5 inches = 0.42 ft (convert inches to feet)
- Surface Area = Length x Height = 12 x 12 = 144 sq ft
- Volume = Surface Area x Thickness
= 144 sq ft x 0.42 ft = 60.48 cubic feet
So the total volume of the 12×12 wall that is 5 inches thick is 60.48 cubic feet.
Using This Calculation
Knowing how to find the square footage of a wall comes in handy for:
- Determining how much paint, wallpaper, tile, etc you need to purchase
- Figuring out flooring requirements
- Measuring for furniture such as bookshelves or tv consoles
- Installing lighting fixtures or electrical outlets
- Remodeling, renovations or additions
- Real estate purposes – calculating total livable space
Square Footage of Common Wall Sizes
Here are some common wall size examples and their total square footages:
| Wall Dimensions | Square Footage |
|---|---|
| 8 ft x 8 ft | 64 sq ft |
| 10 ft x 10 ft | 100 sq ft |
| 10 ft x 12 ft | 120 sq ft |
| 12 ft x 12 ft | 144 sq ft |
| 20 ft x 20 ft | 400 sq ft |
Finding Square Footage for Rectangular Rooms
The same formula applies when calculating the total square footage of rectangular shaped rooms or spaces:
Length x Width = Total Square Feet
Some examples:
- Bedroom: 10 ft x 12 ft = 120 sq ft
- Living room: 15 ft x 20 ft = 300 sq ft
- Garage: 20 ft x 22 ft = 440 sq ft
Make sure to take multiple measurements if the walls are not perfectly rectangular. Add together the square footages of each wall to get the total.
For Irregular Shaped Spaces
If you are trying to find the square footage of an irregular, non-rectangular shaped space, here are some options:
- Break the area down into rectangular sections, measure and calculate each section separately, then add them together.
- Use an online calculator that allows you to input custom dimensions.
- Use a measuring wheel to manually roll across the floor and get the total square footage.
- Sketch the outline on grid paper and count the squares.
Using Area Measurement Apps
There are various apps available for smartphones and tablets that make it easy to measure a space and determine the square footage instantly. Here are some of the top options:
- MagicPlan – Uses your phone’s camera to create a floor plan.
- RoomScan Pro – Laser-assisted measurement for floor plans.
- Measure – Allows you to draw floorplans and has AR measuring.
- Roomle – Imports images to make interactive floor plans.
These apps eliminate the need for manually measuring and calculating the area yourself. Many of the apps use augmented reality to scan the space with your smartphone camera and instantly generate the dimensions and floor plan layout.
Benefits of Using a Measurement App
- Saves time and effort over manual measuring.
- Very accurate since it uses sensors and AI technology.
- Easy to edit, update, and share results.
- Works for both rectangular and oddly-shaped spaces.
- Can add dimensions, notes, photos to floor plans.
Factors that Affect Square Footage Calculations
When determining square footage, keep in mind some factors that can influence the measurements:
- Crown molding – Crown molding extends the wall dimensions slightly. Take measurements from the floor to get exact wall height.
- Baseboards – Baseboards can also add a small amount to the wall length. Measure above baseboards for accuracy.
- Irregular dimensions – Older homes often have walls and rooms that are not perfectly rectangular. Take multiple measurements.
- Vaulted ceilings – Vaults, slopes and angled ceilings make the wall height inconsistent. Measure each section separately.
- Outlets, vents and fixtures – Protruding objects reduce the flat surface area. Consider offsetting deductions if needed.
- Corner roundness – Outside corners may have a rounded edge rather than 90 degrees. Use the shortest wall dimensions.
Taking these factors into account and deducting any offsets will give you the most accurate square footage possible.
Conclusion
Finding the square footage of a wall, room or irregularly-shaped space is simple with just a bit of measurement and math. For a basic rectangular wall or room, multiply the length times the width to get the area in square feet. Be sure to take multiple measurements if the walls are not perfect rectangles. For odd-shaped areas, either break it down into rectangles or use a measuring app for convenience and accuracy. With the right tools and technique, you can quickly find the square footage you need for flooring, tile, lighting, remodeling and real estate purposes.
