A drywall calculator starts from the wall area calculator and ends at the quote: the square feet of wall and ceiling to be covered, divided by the area of the sheet chosen, plus the contractor's waste allowance, gives the sheets; the sheets give the mud, the tape and the screws; and the sheets times the contractor's own rate to hang and finish give the drywall estimate. Each step is arithmetic on figures the contractor already has, and each is done differently by a lead in a hurry, which is how a 22-sheet room gets quoted at 18. This page works the sheets, the materials and the cost on a 12 by 14 foot room with 8-foot walls, and the free construction cost estimator on this site carries the result into the estimate at your own rates, with no account.
The wall area calculator: square feet of wall and ceiling
Wall area is the room's perimeter times the wall height; ceiling area is length times width. A 12 by 14 foot room has a perimeter of 52 feet; at 8-foot walls that is 416 square feet of wall, and the ceiling is 168 square feet, 584 square feet in all. Openings are handled two ways: deduct them (a 3 by 7 door is 21 square feet, a 3 by 4 window is 12) for a tight count, or leave them in as the waste allowance for a room with few of them. On the worked room with one door and one window deducted, the area is 551 square feet. A drywall calculator for walls and a drywall calculator for ceiling are the two halves of the same sum, kept separate because ceiling sheets are often a different thickness.
The drywall material calculator: sheets, mud, tape and screws
Sheets equals area divided by the sheet's area, plus waste. A 4 by 8 sheet is 32 square feet; 551 square feet divided by 32 is 17.2 sheets, and at a 10% waste allowance the count is 19; with the openings left in as the allowance instead, 584 divided by 32 is 18.3, rounded to 19 as well, and a lead who wants a sheet in hand orders 20. On 4 by 12 sheets, 48 square feet each, the count is 12 or 13 with fewer joints to finish. Mud, tape and screws are then per sheet, at the coverage the products state: joint compound by the gallon or bucket per hundred square feet, tape by the roll per number of joints, screws by the pound per sheet. The Gypsum Association publishes the standards the board and the finish levels are specified against.
The drywall estimate calculator: hanging, finishing and the cost
The drywall installation cost calculator is the sheet count times the contractor's own rate to hang, and the drywall finishing cost calculator is the finished area times the contractor's own rate to tape, mud and sand to the level specified, plus the materials. On the worked room, 19 sheets hung at the contractor's per-sheet rate, 551 square feet finished at the contractor's per-square-foot rate for the finish level, and the materials at the supplier's prices, added and marked up at the contractor's overhead and profit, is the drywall estimate. The rates are yours; the calculator's job is to multiply them by the right count, which is where the 18-sheet quote for a 22-sheet room came from.
The drywall quote: what the number on the page has to show
A drywall quote the owner can read shows the area, the sheet count and size, the finish level, the materials, the labor to hang and to finish, and the total, so a change to the finish level or a second coat of primer is a change to a visible line rather than a new number. The free construction cost estimator on this site carries the drywall as a line in the whole job's estimate, at the contractor's own cost per square foot with site work, contingency and overhead and profit shown, and the schedule of values then carries the same line as the drywall's value for the draw. One count of sheets, done once, is what those three documents agree on.
Questions people ask about drywall calculator
How many sheets of drywall for a 12 by 14 room?
With 8-foot walls, 416 square feet of wall and 168 of ceiling, 584 square feet in all; on 4 by 8 sheets with the openings left in as waste, 19 sheets, 20 with one in hand. On 4 by 12 sheets, 12 or 13.
How is drywall mud calculated?
Per sheet or per hundred square feet at the coverage the product states, which differs between all-purpose, lightweight and setting compounds and between finish levels. The sheet count from the calculator drives it.
What does a drywall installation cost calculator need from me?
Your own rate to hang per sheet, your rate to finish per square foot at the specified level, and the supplier's prices for board, mud, tape and screws. It multiplies them by the counts; the rates are yours.