Drywall Calculator
Estimate how many sheets of drywall you need for walls and ceilings, then get mud, tape, screws, and optional cost in the same pass. Door and window deductions are built in, so the order stays closer to what you actually need to buy.
Build Your Drywall Order
Start with room size, ceiling, and openings. Then choose the sheet size and drywall type that make the most sense for the room.
Room dimensions
8 ft is the most common starting point.
Openings to deduct
Standard door deduction: 21 sq ft each.
Standard window deduction: 12 sq ft each.
Drywall choices
Most common — fits through doorways easily (54 lbs each)
Living rooms, bedrooms, hallways
Use more waste when the room has extra cuts, awkward corners, or taller openings.
Drywall Order Summary
This is a standard wall-only room count, which makes it a good first pass before adding specialty boards or ceiling coverage.
Additional materials
Optional cost
Checks and math
Open this to check the area deductions and calculation steps.
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Checks and math
Open this to check the area deductions and calculation steps.
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Worked examples
How many sheets for a 10x10 room
10 x 10 ft room · 8 ft walls · 1 door · 4x8 standard drywall
A good fit for a small room when you are only covering the walls and want a quick read on sheets, mud, tape, and screws.
How many sheets for a 12x12 room with ceiling
12 x 12 ft room · 8 ft walls · 1 door · 1 window · ceiling included
This is the kind of order people often miss on the first pass because the ceiling adds more sheets than the walls alone suggest.
Garage with Type X drywall
20 x 12 ft enclosed area · 8 ft walls · garage layout · Type X drywall · ceiling included
A useful reference when you need a heavier board for garage or code-driven work. Large garage door openings should still be adjusted separately.
Drywall size guide
4×8 drywall sheets
Most rooms and the easiest handling
The most common choice for DIY work. Easier to carry, easier to move through the house, and usually the safest place to start.
4×10 drywall sheets
Taller walls with fewer seams
A good middle ground when you want fewer horizontal seams without taking on the full weight of a 4×12 sheet.
4×12 drywall sheets
Long runs when you have help
Best when seam reduction matters more than convenience. The larger sheet saves finishing time, but it is much harder to move and lift.
Which drywall type should I use?
1/2" Standard
Living rooms, bedrooms, and most walls
The normal choice for most interior rooms. Stick with this unless moisture or code rules push you to another board.
1/2" Moisture-Resistant
Bathrooms, kitchens, and laundry rooms
A better fit where humidity matters, but not a replacement for cement board in direct wet zones like showers.
5/8" Type X
Garages and code-driven ceilings or shared walls
The heavier board you will often need when fire resistance matters, especially around attached garage areas.
5/8" Soundproof
Bedrooms, offices, and media rooms
Worth considering when noise reduction matters enough to justify the added weight and cost.
How we calculate
Example
- 12×10 room with 8 ft walls = 352 sq ft wall area
- Subtract 1 door + 1 window = 319 sq ft net area
- 319 ÷ 32 sq ft per 4×8 sheet = 10 sheets
- With 10% waste = 11 sheets to buy
Material rules
- Screws: about 32 per 4×8 sheet
- Joint tape: about 2 linear ft per sheet
- Joint compound: about 1 gallon per 180 sq ft
- Corner bead: 4 vertical corners plus ceiling perimeter when needed
Standard door and window deductions are built in. Large openings, such as garage doors or unusual vaulted areas, should still be adjusted separately before ordering.