You have decided you would like to apply vinyl siding to your home, and why not?

Vinyl siding has become one of the most popular exterior finishes in North America. It is available in dozens of colors and a wide range of styles and if you’re renovating, new siding can give your home a brand new look.  Vinyl siding can protect your home from the elements, and is resistant to vermin and chemical damage.  It is long lasting, low maintenance and strong enough to withstand high winds and  harsh rain.

Before you begin a siding job, or before hiring an installer to do the job for you, it is helpful to get an idea of how much material you will need to be able to estimate the cost of materials. This initial information will give you the knowledge to help budget the project and if you hire someone to install the siding, you will have a knowledgeable basis from which to negotiate a price.

Step One: Take Measurements

To start, you will need: a pencil, paper, measuring tape and ladder. Generally, what you will be doing is measuring and recording the height and width of each wall to be sided.

1.  Make a rough sketch of your house

This step will make it easier to keep track of the measurements as you go.  All houses can be broken down into shapes of rectangles or triangles, or a combination of both.

2.  Measure the height (ground to top) and length (side to side) in feet and write this down on your sketch

The area to be sided can be determined by measuring the height and width of the house. Start by choosing one side of the house to be sided.

3. Measure the rectangular wall to be sided

Do not include gables – yet.  These will be considered in step 4.  Windows and doors are not usually deducted. Including them will provide an allowance factor for waste. If the windows and doors are extremely large, such as a garage or sliding glass doors, some deductions can be made.

Continue measuring and recording the remaining rectangular walls to be sided.

4. Measure and record all gable walls as triangles

Include base length, and a perpendicular distance from base to peak (height).

5. Find the area of a rectangular wall by multiplying their length and height

The result is the area of the rectangle wall.

Length _________feet X Width ________feet =  Area of Wall

6. Find the area of the gable by multiplying base length by the height and dividing by 2

(Length  ______feet   x   Width  _________feet) ___________________________________________      = Area of Gable                                                     2


7. Find the total area of the walls by adding your gable and rectangle wall area


8. Add another 10% to make up for the wasted siding when cutting to length

It is better to order too much than to come up short. Make sure to check the return policy before making your purchase.

You now have your square footage calculation for the siding.

9. Measure the amount of starter strip you will need

To estimate the amount of starter strip required, measure the linear feet around the entire base of the house.

10.  Measure the distance in feet around all windows and doors

This will be the amount of trim required. Add 10% to this for the excess required.

11. Measure the amount of j-channel you will need

Take and add only the measurements of the tops of each window and door to get the length of j-channel you will need.

12. Measure the height of inward and outward corners

Do these separately. Make sure you measure any design feature of you home that creates a corner, such as inset doors or bumped out windows. You will need to purchase trim for corners.

 Step Two: Price your Project

To estimate the cost of a vinyl siding project, it is a good idea to select a couple of siding choices that vary in price point, especially if cost is a factor.

The cost of the vinyl siding itself will be determined by the style, color, quality, thickness and whether or not it is insulated.  In addition, a vinyl siding project involves assorted trims, corners and channels to direct water and cover joins. Contact your local retail location or consult with your contractor for pricing.  To get a general idea of the cost of your siding project, take all of your measurements for each item separately, and multiply the running or square footage of by the dollar amount per foot or square foot of each item.

For example:

Wall area in square feet x price of vinyl per square foot = cost per square foot

Starter strip in feet x price of starter strip per foot = cost per foot

If you made more than one brand or style choice, calculate an estimate, one at a time, for each of your different siding package options.

Keep in mind, the above process is only a guideline to calculate vinyl siding and the trim.  There are other factors to consider for your vinyl siding application project including:

  • Soffit and fascia
  • Nails and fasteners
  • Tools
  • Sheathing
  • Water resistant barrier
  • Removal cost for existing siding
  • Cost for installation

You can now bring these measurements to a vinyl siding dealer where they can give you a more accurate breakdown of the cost.