Prehung Door Sizes
A prehung door is a complete door unit with the door slab already mounted inside a frame. Prehung doors are commonly used in residential construction because the frame, hinges, and door are supplied as an assembled unit.
Common Prehung Door Sizes
| Nominal Door Size | Door Width | Door Height | Typical Rough Opening |
|---|---|---|---|
| 24 × 80 | 24 in. | 80 in. | Approx. 26 × 82 in. |
| 28 × 80 | 28 in. | 80 in. | Approx. 30 × 82 in. |
| 30 × 80 | 30 in. | 80 in. | Approx. 32 × 82 in. |
| 32 × 80 | 32 in. | 80 in. | Approx. 34 × 82 in. |
| 36 × 80 | 36 in. | 80 in. | Approx. 38 × 82 in. |
The rough opening values above are common planning references. Actual prehung unit and rough opening dimensions vary by manufacturer and frame configuration.
What Is Included With a Prehung Door?
A typical prehung door package includes the door slab, frame, and hinges. Some products may also include additional hardware or installation components. The exact contents depend on the manufacturer and product.
Because the door is already installed in its frame, the overall dimensions of the prehung unit are larger than the nominal door slab dimensions.
Prehung Door Size vs Rough Opening
The prehung unit must fit inside the rough opening. The rough opening is normally larger than the assembled door unit so the installer has room to position, shim, level, and secure the frame.
For example, a nominal 30 × 80 door may use a prehung unit that is larger than the door slab but still smaller than a rough opening of approximately 32 × 82 inches.
Important Measurements
| Measurement | What It Describes |
|---|---|
| Door slab width | The physical width of the door itself. |
| Door slab height | The physical height of the door itself. |
| Unit width | The overall width of the assembled prehung door and frame. |
| Unit height | The overall height of the assembled prehung door and frame. |
| Rough opening | The framed wall opening prepared for installation. |
Related Door Size References
FAQ
What is a prehung door?
A prehung door is a door slab that has already been installed in its frame, usually with hinges attached.
Does a prehung door include the frame?
Yes. The defining feature of a prehung door is that the door comes mounted in a frame as an assembled unit.
Is a prehung door the same size as the rough opening?
No. The rough opening is normally larger than the prehung unit to provide space for installation and adjustment.
Should I verify the manufacturer's dimensions?
Yes. Prehung unit dimensions and required rough openings can vary by manufacturer, frame material, and product design.