Guide to Drywall Thickness, Length, and Width

Standard sizing is one of the drywall's best features. With each sheet of drywall, you know in advance its exact thickness of the drywall and its length and width, down to the millimeter. Predictable sizing allows builders and homeowners to plan their projects and hang drywall with complete accuracy.

Drywall Length and Width

The length and width of drywall sheets are usually in multiples of 4 feet—most commonly, 4-foot by 8-foot, 4-foot by 12-foot, or 4-foot by 16-foot sheets. While drywall's lengths are variable, its width generally remains 4 feet.

Building codes often have specific requirements for the thickness of drywall sheets but not for the width and length. These are determined by the needs of the architect, builder, and client. 

4-Foot by 8-Foot Drywall

The most common size of drywall is 4 feet wide and 8 feet long.

Since 1/2-inch thick sheets of 4- by 8-foot drywall tip the scales at 57 pounds, this size tends to be the biggest sheet that most do-it-yourselfers can carry and lift into place.

The 4-foot by 8-foot size allows for either vertical or horizontal installation. Typically 4 by 8-foot panels come attached in pairs—two sheets face to face, with paper strips binding the two sheets. Most people find it extremely difficult to carry these sandwiched panels by themselves, and they can be difficult to cut. For solo transport, you can pull off the binding paper to separate the panels.

4-Foot by 12- or 16-Foot Drywall

For tall or long walls, drywall in 12-foot and 16-foot lengths is available.

One advantage of these longer sheets is that you can create a smooth vertical surface to meet higher ceilings, creating a smooth surface that is completely unbroken from floor to ceiling.

Sixteen-foot-long drywall, when installed horizontally on a wall, produces fewer butt joints than 8-foot-long sheets. If you are intending to work with 16-foot lengths of drywall, you need to have several people on hand to help you with the installation.

2-Foot by 2-Foot Drywall

The 2-foot by 2-foot square of drywall is not a stock sheet size. However, cut-down pieces of drywall are often available at most home centers and especially at smaller local hardware stores. These small sheets can be useful for patching jobs or wall-boarding small nooks and alcoves. 

Alternative Sizes of Drywall

When wall panels come in lengths and widths other than these multiples of 4 feet, they are usually not drywall panels but are instead cement board or a drywall alternative, such as DRIcor Smartwall. 

While not common on the consumer market, 4 1/2-foot-wide drywall sheets can be special-ordered. They are not stocked in home improvement centers and are rarely used except by professionals. 

Thickness of Drywall

Common drywall thicknesses are 1/4-inch, 1/2-inch, and 5/8-inch. Building codes do have some requirements when it comes to the thickness of drywall panels. The thickness required for each application is dictated by the building code. 

1/4-Inch-Thick Drywall

Not a common thickness, 1/4-inch-thick drywall is used as a skimming (or double-wall) material for placing over an existing surface or for bending drywall.

While not a common application, drywall sheets that are 1/4-inch thick are valuable when you need to install drywall on slightly curved surfaces. If the drywall is not quite meeting the curve, you can slightly dampen the drywall to make it more flexible.

1/2-Inch-Thick Drywall

Half-inch drywall panels are the standard thickness for interior walls, as well as ceilings. Half-inch drywall panels are relatively easy to carry and hang. Consider 1/2-inch drywall to be the default thickness of drywall for most wall applications.

5/8-Inch-Thick Drywall

These panels are commonly used for ceilings or for walls that require a prescribed fire-resistant rating.

When installed on ceilings, 5/8-inch-thick panels are less susceptible to sagging between the joists than 1/2-inch panels. Adding popcorn texture or another type of heavy surfacing material can add to the weight problem, making 5/8-inch drywall a better choice for ceilings.

3/4-Inch-Thick Drywall

In a practical sense, the thickness of drywall maxes out at 5/8-inch. But 3/4-inch drywall does exist and it is used on steel-framed walls for fire proofing. Walls must be able to support 3/4-inch drywall since 4-foot by 10-foot sheets weigh about 112 pounds.

Fire-Rated 5/8-Inch Thick Drywall

Two forms of 5/8-inch drywall sheets are used for walls and ceilings in certain areas that may experience fire: Type X drywall (mainly for walls) and Type C drywall (mainly for ceilings).

5/8-Inch-Thick Type X Drywall

Thicker drywall may be required by code for any surface covered with a texture or skim coat where studs or joists are spaced 24 inches on-center rather than 16 inches. Though Type X drywall can be used on ceilings or walls, it is primarily installed on walls.

This thicker drywall is often called Type X or fire-resistant drywall. Common walls between residential living spaces and attached garages, for example, require a fire-resistant construction, as do furnace rooms. This fire resistance can also be achieved by installing multiple layers of thinner drywall panels. 

The difference between conventional 5/8-inch-thick drywall and Type X 5/8-inch drywall is the presence of proprietary additives (mainly glass fibers) that enhance its fire resistance.

5/8-Inch-Thick Type C Drywall

Type C drywall is similar to Type X drywall: both are fire-rated and contain a high quantity of glass fibers.

The difference between Type C and Type X drywall is that Type C drywall has more glass fibers than Type X and also has vermiculite. Vermiculite is added to help prevent the panels from shrinking. Vermiculite expands when subjected to fire.

Type C drywall is more often used on ceilings than Type X, which is more for walls.