Calculating the cost of finishing the drywall in your home is simple. You need to know how to do basic math, and if you are not good with math, a calculator is extremely helpful. Many things are involved in the finishing of drywall, a lot depending on how far along your home or room or wall is that needs to be finished. For the purpose of general calculation, consider starting from the point of bare framing.
Measure the length and height of the wall or walls for which the drywall needs to be finished. Multiply the length of the wall by the height to determine the square footage of drywall you will need. Drywall sheets come in 8-foot, 10-foot and 12-foot sheets and are available in 4-foot and 4-1/2-foot widths.
These measurements will help you calculate the square footage of drywall per sheet. Repeat this step for each surface area that needs drywall finishing.
You should hang drywall horizontally, so if you have 8- or 9-foot ceilings, the sheets will be stacked two high. If the wall that needs finishing is less than 12-feet long, you will not need multiple sheets per length; if it's over 12 feet, you will need to calculate for extra sheets to make up the difference.
Sheets of drywall need a minimum of five screws per stud when hung. Count the studs to determine how many, and multiply that number by 5; then multiply that number by how many sheets high your wall is. This is the minimum number of screws you will need.
To tape the drywall once it is hung, purchase paper tape or mesh tape. You will need to also have a pan for drywall compound and drywall taping knives of different widths: 5-inch, 8-inch and 10-inch.
You will need to have drywall joint or all-purpose compound and drywall topping compound. The amount of each type of compound needed will depend on the area you need to finish and your personal skill level.
You need to have sanding sponges and/or other drywall sanding tools.
Write down all of your calculations and supply list. Go to your local hardware store, and locate prices of each item you will need. Calculate the cost for the quantity of each item you need. This will give you your total cost.
If you want to have a textured wall instead of a smooth wall, texture sprayers are available from most equipment rental shops. Call your local shop to determine cost of rental. Ask a rental agent for an estimate of how many square feet the sprayer will cover per bucket of drywall compound. Calculate the cost of compound for the square footage you need to texture.
If you decide you cannot accomplish the finishing of your drywall, ask friends and family for recommendations of drywall contractors. Call many drywall contractors to see if they are available to place bids on finishing the drywall in your home. Collect and compare several bids, and ask the drywall contractors for references so that you can see their work. Choose a contractor based on the quality of their work and the costs of their bids.
Drywall contractors will usually give you a price per square foot to include hanging the drywall, taping the drywall and finishing the drywall. Contractors tend to like to hang the drywall themselves due to joint placement and breakage, but most will work with you if the drywall is already hung.