🚪 Door Size Calculator
Find the perfect door dimensions, rough opening size, and door frame measurements instantly
| Door Type | Nominal Width | Nominal Height | Rough Opening W | Rough Opening H | Metric Width |
|---|---|---|---|---|---|
| Bathroom Interior | 28" | 80" | 30" | 82.5" | 711 mm |
| Bedroom Interior | 30" | 80" | 32" | 82.5" | 762 mm |
| Standard Interior | 32" | 80" | 34" | 82.5" | 813 mm |
| Exterior / Entry | 36" | 80" | 38" | 82.5" | 914 mm |
| ADA Compliant | 36" | 80" | 38" | 82.5" | 914 mm |
| French Door (pair) | 60" | 80" | 62" | 82.5" | 1524 mm |
| Sliding Patio | 72" | 80" | 74" | 82.5" | 1829 mm |
| Garage Single | 96" | 84" | 98" | 86.5" | 2438 mm |
| Tall Door | 36" | 96" | 38" | 98.5" | 914 mm |
| Bifold Closet | 24" | 80" | 26" | 82.5" | 610 mm |
| Installation Type | Width Add | Height Add | Notes |
|---|---|---|---|
| Prehung Door (standard) | +2" | +2.5" | Most common residential |
| Door Slab Only | +1.5" | +2" | Existing frame replacement |
| Masonry / Concrete | +2.5" | +3" | Allows for more shimming |
| Fire-Rated Door | +2" | +2.5" | Frame must be fire-rated too |
| Pocket Door | +2 x door width | +2.5" | Wall cavity = 2x door width |
| Barn Door (surface) | +12" overlap | +2" | Track above opening |
| Door Type | Standard Thickness | Metric | Typical Use |
|---|---|---|---|
| Hollow Core Interior | 1-3/8" | 35 mm | Lightweight interior |
| Solid Core Interior | 1-3/4" | 44 mm | Soundproofing, privacy |
| Exterior Wood | 1-3/4" | 44 mm | Entry, back door |
| Steel / Fiberglass | 1-3/4" | 44 mm | Exterior security |
| Fire-Rated | 1-3/4" | 44 mm | Required by fire code |
| Garage Sectional | 2" | 51 mm | Insulated garage door |
| Requirement | Imperial | Metric | Standard Reference |
|---|---|---|---|
| Minimum clear width | 32" | 813 mm | ADA 404.2.3 |
| Preferred clear width | 36" | 914 mm | Recommended for wheelchair |
| Maximum door weight | 5 lbf | 22 N | Force to open |
| Handle height | 34"–48" | 864–1219 mm | ADA 404.2.7 |
| Threshold max height | 1/2" | 13 mm | ADA 404.2.5 |
| Maneuvering clearance | 18" latch side | 457 mm | ADA 404.2.4 |
The typical size of exterior Door is 80 inches tall and 36 inches wide. This matches 6 feet 8 inches tall and 3 feet wide. In modern houses you commonly find heights of 96 inches, or 8 feet.
Exterior doors come also in 30- and 32-inch widths. The standard Door height in the whole sector stays 80 inches so 6 feet 8 inches. Even so, if one measures the actual Door frame, it normally shows around one inch lower than 6 feet 8 inches.
Common Door Sizes and How to Measure
Entry front doors usually have 36 inches wide and 80 inches tall, commonly called 3068 or 3/0 x 6/8. Back doors most commonly are 32 inches by 80 inches, same as internal doors. For bedrooms one prefers widths of 30 or 32 inches.
Bathroom doors occasionally go down to 24 inches narrow. Before it was simple to get doors in stores in every 2 icnhes between 24 and 36, but today the standard options limit to 24, 30 and 36 inches.
The usual standard for doors measures 80 inches tall and 36 inches wide. The rough opening must be a bit wider. Useful advice says that the rough opening should be around 2½ inches wider and 2¼ inches higher than the Door frame.
Like this for a Door of 36 by 80 inches, the opening measures 38 inches wide and 82 inches tall. For a 30-inch Door one needs usually a 32-inch rough opening.
Big doors allow wide entry, but need more space to open. In big or special houses it is possible too find doors up to 42 inches wide or even more. Commercial buildings commonly use standards with even wider doors.
Any Door above 36 inches wide, especially at 8-foot heights, seems heavy and difficult for many as exterior entry.
Rules of ADA require that each Door opening at least 32 inches wide and no more than 48 inches, for easy access by means of wheelchair. ADA requires minimal 36-inch Door or more, so the rough openings must be 2 to 2½ inches bigger. Building codes also matter.
One exit Door, usually the front, must have clear width of 32 inches. So the smallest front Door ultimately measures around 34 inches.
For a replacement Door, just measure the width at the widest place and the height from top to bottom. At a new Door, add 2 inches to all sizes to help for good fit and cleanup. In United Kingdom an internal Door commonly has 1981 mm tall and 762 mm wide, what is roughly 6 feet 6 inches by 30 inches.
Here the rough opening must be around 2 inches wider and 2½ inches higher than the frame. Metric sizes can seem hard to recall. Door 3-0 by 7-0 converts to 915 mm by2143 mm.
