Door Rough Opening Sizes
A rough opening is the framed opening in a wall before a door unit is installed. The rough opening is normally slightly larger than the actual door or prehung door unit to allow for installation, shimming, leveling, and adjustment.
Common Door Rough Opening Sizes
| Door Size | Approx. Rough Opening Width | Approx. Rough Opening Height |
|---|---|---|
| 24 × 80 | 26 × 82 | 82 in. |
| 28 × 80 | 30 × 82 | 82 in. |
| 30 × 80 | 32 × 82 | 82 in. |
| 32 × 80 | 34 × 82 | 82 in. |
| 34 × 80 | 36 × 82 | 82 in. |
| 36 × 80 | 38 × 82 | 82 in. |
| 36 × 84 | 38 × 86 | 86 in. |
| 36 × 96 | 38 × 98 | 98 in. |
These dimensions are common planning references. Exact rough opening requirements can vary by door manufacturer, frame type, installation method, and building conditions.
How Much Larger Is a Rough Opening?
For many standard prehung doors, the rough opening is approximately 2 inches wider and 2 inches taller than the nominal door size. This provides space for the frame and installation adjustments.
For example, a nominal 30 × 80 inch door commonly uses a rough opening of approximately 32 × 82 inches. Always check the manufacturer's installation instructions before framing a new opening.
Rough Opening vs. Door Size
| Term | Meaning |
|---|---|
| Nominal door size | The commonly stated door size, such as 30 × 80 inches. |
| Actual door slab | The physical dimensions of the door itself, which may be slightly smaller than the nominal size. |
| Rough opening | The framed wall opening prepared to receive the door unit. |
| Prehung door | A door supplied with its frame and hinges already assembled. |
Related Door Size References
FAQ
What is a standard rough opening for a 30 × 80 door?
A commonly used rough opening is approximately 32 × 82 inches, although the exact requirement depends on the door and frame manufacturer.
Is the rough opening bigger than the door?
Yes. The rough opening is normally larger than the nominal door size so the frame can be installed, shimmed, leveled, and adjusted.
Should I use the rough opening size from a chart?
Use a chart as a planning reference, but verify the manufacturer's specified rough opening before construction or ordering materials.