1. To calculate the square footage of the area you want to drywall. Multiply height times the width of each wall section and/or ceiling section (if you’re doing the ceiling). Add each of these sections up. This gives you the total square footage.
2. Cost of Drywall- If you are using 4×8 feet sheets of drywall, then divide the total square footage by 32. If using 4×12 sheets of drywall, then divide by 48. This will tell you how many panels of drywall you will need. Multiple this by the cost of drywall panels, plus sales tax.
3. Cost of Joint Tape- For 4×8 panels multiply the number of drywall pieces by 24, if using 4×12 just multiply the sheet count times 36. This gives you the linear feet of drywall tape needed. Tape usually comes in 250 feet rolls or 500 feet rolls. Divide the linear feet by the tape length and you’ll get the number of rolls needed. Multiply the per roll cost times the number of rolls needed.
4. Drywall Mud/Compound Mix- Take the drywall square footage from #1 and divide by 400. This is how many buckets of ready-mixed joint compound you will need. Multiply this times the cost per bucket and you’ll have the total cost.
5. Screws/Nails Needed- Divide the total square footage of drywall by 300. This is how many POUNDS of 1.25 inch length drywall screws are required. You must use at least 1.25 inch length drywall screws. Note the cost per box and multiply as needed. Most building codes require twice the amount of nails per panel of drywall.
6. Corner Bead (if you need it)- Add the length of all the corners. Corner bead for drywall usually comes in eight and ten foot sections. Multiply the number of sections by the price per piece accordingly.
7. Labor Costs (if applicable)- Total up the costs above. This is your “installation price”. Add in some fees for a dumpster, if needed. Mark this up by about 20% (multiply your installation price plus other fees times 1.20). This results in about how much a contractor will charge you.

Ron Johnson (Owner) Lake City Drywall & Paint