Drywall · ceiling
How much drywall does a ceiling need?
A ceiling is one rectangle: length times width. Then the two things that actually go wrong — board too thin for the joists, and nobody free to hold the other end.
- Length × width only
- Screw spacing accounted for
- Ceiling-first advice
The room
Sheet size
Thickness
Stiffer, so it sags less on ceilings. Also the usual Type X fire rating.
Waste is 10%, 0 outside corners. Defaults are fine for most rooms.
Room plan
shape only, not to scale
You need
8sheets
4 × 8 ft · 5/8 in · 10% waste
Materials
$210
at your prices
- Ceiling
- 224 sq ft
- Net area to board
- 224 sq ft
- Sheets before waste
- 7 → 8
- Weight to carry
- 561 lb
What to put in the cart
Finishing follows the manufacturer coverage rates: 10 gal of mud and 370 ft of tape per 1,000 sq ft.
- 1$166
8 × 4 × 8 ft 5/8 in drywall sheets
- 2$18
2 × 1 lb box of 1-5/8 in drywall screws (about 245 screws)
- 3$7
1 × 250 ft roll of paper joint tape (83 ft needed)
- 4$19
1 × 4.5 gal pail of all-purpose joint compound (2.2 gal needed)
The whole setup lives in the link — send it to whoever is helping.
Your rooms
A renovation is never one wall. Save each room here and load it when you get to it — kept in this browser only, no account needed.
Nothing saved yet. Set up a wall above, then hit Save this room.
Worked example: A 14 × 16 ft ceiling in 5/8 in board
224 sq ft, 4 × 8 sheets, 10% waste. No walls, no openings — this page counts the ceiling and nothing else.
| Walls | 0 sq ft |
| Ceiling | 224 sq ft |
| Openings | none |
| Net area to board | 224 sq ft |
| Sheets before waste | 7 |
| Sheets to buy | 8 |
| Screws | 245 (about 2 lb) |
| Paper tape | 83 ft (1 × 250 ft) |
| Joint compound | 2.2 gal (1 × 4.5 gal) |
| Weight on the truck | 561 lb |
| Heaviest single sheet | 70 lb |
Half-inch board sags between joists after a few winters, and you find out when the paint starts showing seams. 5/8 costs 23% more weight. That is still cheaper than repainting a ceiling.
Turn the ceiling off and it drops to 0 sheets — that toggle is worth 8 sheets, or about 100% of the job.
Where these numbers come from
Three steps. Every coefficient is a published figure, so you can redo any of it on paper.
- 1
One rectangle
Length times width. 14 × 16 = 224 sq ft. No perimeter in this sum — a ceiling and a wall are different formulas, which is why these are separate pages.
- 2
Ceilings are screwed tighter
Manufacturers want fasteners at 12 in on a ceiling against 16 in on a wall, so a 4 × 8 sheet takes about 35 screws instead of 28. Switch the board thickness and the screw gauge changes with it — 1-5/8 in for 5/8 board, not 1-1/4.
- 3
Waste is about the last row
A ceiling is usually not a whole number of sheets wide. The last course is a rip, and a long rip down the length of a room is where the 10% goes. Rooms with a chimney breast or a light well need 15%.
Joint compound
10 gal
per 1,000 sq ft of board
Paper tape
370 ft
per 1,000 sq ft of board
Fasteners
16 in / 12 in
walls / ceilings, on centre
What this calculator cannot know
Four things the number has no way of seeing. Better to read them now than at the counter.
- It assumes a flat, level ceiling. A sloped or cathedral ceiling has more surface than its footprint — measure the slope length, not the plan view, or the board count will come in low.
- It does not add for the box or bulkhead around a duct, a beam, or a dropped section. Each one adds board and four inside corners to tape.
- It counts the ceiling only. If the same job includes the walls, run them as a separate room calculation and add the two — mixing them into one number makes both wrong.
- It cannot tell you whether the board will hold. That is joist spacing and thickness, and at 24 in centres with 1/2 in board the answer is usually "it will sag".
Questions people actually ask
Including the ones where the honest answer is “ask your inspector”.
How many sheets of drywall for a 14 × 16 ceiling?
224 sq ft, so seven sheets of 4 × 8 with nothing left over, or eight once you add 10% for the rip along the last course. In 5/8 in board those eight sheets weigh 561 lb in total and 70 lb each — that is a two-person job, or a lift.
Should a ceiling be 1/2 in or 5/8 in drywall?
Five-eighths if the joists are at 24 in centres, or if there is a room above that you want some sound separation from. Half-inch is acceptable at 16 in centres and is what a lot of builders use anyway. Thickness does not change the sheet count, only the weight and the screw length.
How many screws per sheet on a ceiling?
About 35 for a 4 × 8 sheet, because ceiling fasteners go at 12 in centres rather than 16. That works out at roughly one and a bit screws per square foot. The calculator above already uses the ceiling rate, not the wall rate.
Can one person drywall a ceiling?
A 4 × 8 sheet of 5/8 in weighs about 70 lb and has to be held overhead while you find a joist. People do it with a deadman T-brace and a lot of swearing. A rental lift for a day costs less than the physio, and it turns a two-person weekend into a one-person morning.
Do I deduct recessed lights from the ceiling area?
No. A 6 in can light is about 0.2 sq ft — a hundred of them would be twenty square feet. Deduct skylights, attic hatches and stair openings, which are measured in tens of square feet, and ignore the small stuff.
Boarding a different room?
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Who wrote this
Shawn Chen
I built these calculators and I keep them up to date. I am not a contractor, so treat this as arithmetic you can check yourself, not as advice from a tradesman.
Last checked and updated
Coverage and fastener figures are the manufacturers' published numbers; the sheet count is the standard area method used across the trade.
Where the numbers come from
- Gypsum Association — GA-216, Application and Finishing of Gypsum Panel Products
- USG — fastener spacing for gypsum board (16 in on walls, 12 in on ceilings)
- USG Sheetrock All Purpose Joint Compound — coverage figures
Coverage and spacing figures are the manufacturers’ own numbers. Where brands disagree, the page uses the lower one.