Skip to main content
Tool Belt Calc

Home improvement

Drywall Calculator

Sheets, screws, tape and compound for a room.

Your measurementsEvery assumption editable01

Set to 0 if you are only boarding the walls.

Covers cuts around openings and damaged edges.

Drywall requiredCalculated live02

Result

17sheets

Buy 17 sheets

Wall area60 ft perimeter × 8 ft high
480 sq ft
Total board area
480 sq ft
With waste allowance+10%
528 sq ft
Sheets requiredat 32 sq ft each
17 sheets
Screwsabout 32 per sheet at 16 in centres
≈ 544
Joint compoundtaping, filling and two finish coats
≈ 6 gallons
Joint tape
≈ 212 linear ft

No deduction is made for doors and windows. Board is normally hung straight over openings and cut out afterwards, which gives a cleaner edge than piecing around the frame.

Longer sheets mean fewer butt joints, and butt joints are the hardest thing to finish invisibly. If the room and your access allow 12 ft boards, they are worth the awkward handling.

Compound and tape figures are for a standard three-coat finish. A level 5 finish with a skim coat over the whole surface needs substantially more.

Enter the perimeter and wall height, add the ceiling area if you are boarding it, and pick your sheet size. It returns the sheet count along with rule-of-thumb figures for screws, joint compound and tape — the three things that get forgotten until the shops have closed.

Why use this tool?What it does differently03

Why use this tool?

The consumables too

Screws, compound and tape are estimated alongside the boards, because running out of compound halfway through taping stops the job just as effectively as running out of board.

All three sheet sizes

4x8, 4x10 and 4x12. Longer boards mean fewer butt joints, which are the hardest joints to finish invisibly.

Walls and ceiling separately

Ceiling area is its own field, so you can board walls only or include the ceiling without a second calculation.

No opening deductions

Board is hung over doors and windows and cut out afterwards. Not deducting them matches how the job is actually done.

How this worksThe method04

How this drywall calculator works

Wall area is perimeter times height, with ceiling area added if you enter one. The waste allowance is applied, then the total is divided by the area of a single sheet and rounded up.

Openings are deliberately not deducted. Hanging board straight across a door or window and cutting the opening out afterwards gives a cleaner, stronger edge than piecing panels around the frame, and it is standard practice — so the board goes on the wall whether or not there is a hole behind it.

The consumables are rules of thumb rather than specifications. Around 32 screws per sheet at 16 inch stud centres, roughly one gallon of ready-mixed compound per 100 square feet of board across taping and two finish coats, and about 0.4 linear feet of tape per square foot. They are close enough to shop from and worth rounding up on.

How to use itStep by step05

How to use it

  1. Step 1: Measure the perimeter

    Add together the length of every wall being boarded. Include walls you are boarding on one side only.

  2. Step 2: Enter the wall height

    Floor to ceiling. Standard is 8 feet, which is exactly why 4x8 sheets hung horizontally suit most rooms.

  3. Step 3: Add the ceiling

    Enter the ceiling's area in square feet if you are boarding it, or leave it at zero for walls only.

  4. Step 4: Pick the sheet size

    Longer boards mean fewer butt joints and a better finish, but they are heavy and awkward. Consider whether you can get a 12 foot sheet into the room at all.

Example usageWorked figures06

Example usage

A 12 by 14 bedroom, walls only
A 52 foot perimeter at 8 feet is 416 square feet, plus 10% is 458. In 4x8 sheets that is 15 boards, about 480 screws, 5 gallons of compound and 184 feet of tape.
The same room including the ceiling
Adding 168 square feet of ceiling brings the total to 643 with waste, or 21 sheets. Ceilings are also where you want the longest boards you can handle, to minimise joints overhead.
A garage in 4x12 sheets
A 100 foot perimeter at 9 feet is 900 square feet, 990 with waste. In 4x12 boards that is 21 sheets rather than the 31 you would need in 4x8 — ten fewer boards and far fewer butt joints.
Frequently asked questionsCommon questions07

Frequently asked questions

How many sheets of drywall do I need?

Divide the total wall and ceiling area by the sheet area — 32 square feet for a 4x8, 40 for a 4x10, 48 for a 4x12 — then add around 10% for waste and round up. This calculator does that and adds the consumables.

Should I deduct doors and windows?

No. Board is normally hung straight over openings and cut out once fixed, which gives a cleaner edge and a stronger panel. Deducting the openings would leave you short.

How much joint compound do I need?

Roughly one gallon of ready-mixed compound per 100 square feet of board, covering taping plus two finish coats. A level 5 finish, which skims the entire surface, needs substantially more.

Are longer sheets worth the hassle?

Usually yes. Butt joints — where two sheet ends meet without a tapered edge — are the hardest joints to hide, and longer boards mean fewer of them. The constraint is whether you can physically manoeuvre a 12 foot sheet into the room.

How many screws per sheet?

About 32 for a 4x8 sheet at 16 inch stud centres, using roughly 8 inch spacing in the field and closer at the edges. Buy more than the estimate — screws are cheap and a stripped one is not reusable.

Related toolsElsewhere on the site08

Browse every tool in Home Improvement Calculators.