Look at the exterior of your home as a series of rectangles and triangles. If looked at properly, and divided up properly, every area of the exterior of your home becomes one of these two shapes. Then measure (and write down) in feet the height and the width of each rectangular shape on the exterior of your home. Round off 1/2 foot to the next largest number. Multiply the height by the width of each rectangle and write this number down. Then add together all of the numbers. The answer is the surface area in square feet of all the rectangular areas on the exterior of your home.

Measure the base and then the height of each triangular-shaped area on the exterior of your home. The base is the longest side of any triangle and the height is the measurement from the point of the triangle opposite the base straight down to the base. Multiply the height times the base and divide by 2. This will give you the number of square feet in each triangle. Write this number down for each triangle. Add together the square footage of each triangle.

Add together the total square footage of all the rectangles plus the total square footage of all the triangles. This gives you a good estimate of the total square footage of the exterior of your home.

Add 3 percent to the sum you got in Step 3. This is a contingency in case there are errors in any of your figures.

Multiply the total square footage you arrived at in Step 4 by the cost per square foot of the vinyl siding you've chosen. This will give you an accurate estimate of the cost to cover the exterior of your home in vinyl siding.

## Things You Will Need

- Tape measure
- Calculator

## Tip

- Take your time when measuring and be as accurate as possible. Mark each area as you measure it with a piece of masking tape so you don't miss any areas or measure any areas twice. Double-check all of your measurements before writing them down.