What Exterior Door Sizes Actually Mean
Exterior doors are sold by nominal size — a rounded label such as 32 x 79 inches — while the door slab you receive is slightly smaller and the rough opening in the wall is slightly larger. A 32 x 79 exterior door has a nominal width of 32 inches and a nominal height of 79 inches; the actual slab is typically about 31.5 x 78.5 inches, and the rough opening is roughly 34 x 80.5 inches to allow for the frame, shims, and leveling. Understanding this three-number system — nominal, actual, rough opening — is the single most important thing a wholesale buyer can learn, because ordering the wrong number is the most common and most expensive mistake in door procurement.
Sizing conventions differ by market. North American stock doors are built around a small set of nominal widths (30, 32, 34, 36 inches) and heights (78, 79, 80 inches), while many export markets work in metric modules. A door labeled 32 x 79 in the US is not the same as a “32 x 79” listing on an overseas marketplace, where the seller may be quoting the frame size rather than the slab. Always confirm which dimension the supplier is quoting before you build a purchase order.
Nominal vs. actual vs. rough opening
- Nominal size — the marketing and ordering label (32 x 79).
- Actual slab size — the physical door leaf, usually 0.5 inch smaller in each direction than nominal.
- Rough opening (RO) — the framed hole in the wall, typically 2 inches wider and 1.5 inches taller than nominal for a single prehung unit.
These are starting points, not universal constants. A prehung door with a thick exterior frame, an adjustable jamb, or a sill extension can push the rough opening wider. When you order in volume, ask the factory for the exact RO drawing for that specific model — it should be part of the technical submittal, not something you calculate yourself.
Why height labels vary: 78, 79, and 80
The 78-, 79-, and 80-inch height labels coexist because they serve different construction methods. A 78-inch door is common in older homes and renovation work where the existing header cannot move. A 79-inch door is a frequent nominal label in wholesale catalogs. An 80-inch door is the modern standard for new construction, where the rough opening is framed to a round number. If a buyer asks where to buy a 32×78 exterior door, the honest answer is that 78-inch heights are usually a special-order or custom-cut item rather than a stock SKU — which is exactly why custom-size capability matters at the wholesale level.
Exterior Door Size Chart: Inches and Rough Openings
The table below gives typical nominal sizes, actual slab dimensions, and rough openings for single prehung exterior doors. Treat the rough opening column as a planning reference and confirm final figures with your supplier’s shop drawing.
| Nominal size (in) | Actual slab (in) | Typical rough opening (in) | Common use |
|---|---|---|---|
| 30 x 78 | 29.5 x 77.5 | 32 x 79.5 | Renovation, tight openings |
| 32 x 78 | 31.5 x 77.5 | 34 x 79.5 | Replacement, older homes |
| 32 x 79 | 31.5 x 78.5 | 34 x 80.5 | Wholesale stock, entry doors |
| 34 x 79 | 33.5 x 78.5 | 36 x 80.5 | Wider single entry |
| 36 x 80 | 35.5 x 79.5 | 38 x 81.5 | New construction standard |
| 36 x 96 | 35.5 x 95.5 | 38 x 97.5 | Tall entry, high ceilings |
For double doors, the math changes. A pair of 32-inch doors (a “64” unit) needs a rough opening of roughly 66 inches wide, and a pair of 36-inch doors needs about 74 inches. Sidelights and side panels add width without adding door leaves: a single 36-inch door with two 14-inch sidelights becomes a unit roughly 64 inches wide in the frame, with a rough opening near 66 inches. When you measure an existing opening for a replacement with sidelights, measure the full frame width, not just the door leaf.
Terms buyers should know
| Term | What it means | Why it matters when buying |
|---|---|---|
| Rough opening (RO) | The framed hole in the wall where the door unit installs | Wrong RO means the unit will not fit without reframing |
| Slab | The door leaf alone, without frame or hardware | Slab orders are cheaper but require an existing frame that matches |
| Sidelight / side panel | Fixed narrow glass panels flanking the door | Adds width and light; changes RO and unit price significantly |
| Prehung | Door already mounted in its frame with hinges and sill | Faster installation, fewer site errors, standard for wholesale projects |
How to Measure for an Exterior Door
Measurement is where wholesale orders succeed or fail. The method depends on whether you are replacing a door in an existing opening or specifying for new construction.
Measuring a replacement opening
- Remove the interior and exterior trim to expose the framing.
- Measure the width at three points — top, middle, bottom — and use the smallest figure.
- Measure the height at three points — left, center, right — and use the smallest figure.
- Measure the wall depth (jamb depth) from interior face to exterior face.
- Note whether the opening is square: measure both diagonals. A difference over 0.25 inch means the frame is out of square and the new unit must be shimmed or the opening corrected.
Those three-point measurements protect you against a wall that is not plumb. A single center measurement can easily be 0.5 inch off, which is enough to reject a prehung unit on site.
Measuring for side lights or side panels
For a door with sidelights, measure the total width across the full frame — door leaf plus both glass panels plus frame — and the total height from finished floor to the head. Do not measure the door leaf alone and assume the sidelights are standard. Sidelight widths commonly run 12 to 14 inches each, but they vary by supplier, and the rough opening must be calculated from the assembled unit width, not the sum of nominal parts. If the opening is brick or masonry, measure the masonry opening and confirm the supplier can provide a matching brick mould or fin.
Measuring for new construction
In new construction, you control the rough opening, so work backward from the door schedule. Decide the nominal door size and configuration first, then frame the opening to the supplier’s RO drawing. Add 1.5 to 2 inches of width and height beyond the nominal unit to leave room for shimming and insulation. This is also the stage to confirm sill height and threshold clearance, especially for doors that open onto a deck or patio.
Popular Exterior Door Styles and Configurations
Style choice drives both the visual result and the specification details — glass area, panel layout, and finish method all change with the style.
Shaker, craftsman, and mission: what actually differs
These three styles are often confused because they share clean, flat-panel geometry, but they are not interchangeable.
- Shaker is the simplest: flat recessed panels with square edges and no applied moulding. It reads as minimal and works with both traditional and modern facades.
- Craftsman adds a distinctive top rail — often a horizontal shelf or dentil detail — and typically pairs with a small square or vertical glass lite. It is strongly associated with early-20th-century American residential architecture.
- Mission is closely related but emphasizes vertical lines and heavier stiles, sometimes with a narrow vertical glass panel. In practice, many suppliers use “craftsman” and “mission” loosely, so specify the panel drawing, not just the style name.
For white finishes, all three styles work well because the flat surfaces show paint evenly and touch up cleanly. If you are sourcing white exterior doors for a project, confirm whether the white is a factory-applied paint or a primer-only finish — a primer-only door must be top-coated on site, and field painting can affect the finish warranty.
Arched, mid-century modern, and traditional
Arched exterior doors use a curved top rail and a matching arched frame; they require a curved rough opening or a rectangular opening with a filler above, so they are almost always a custom item. Mid-century modern exterior doors favor asymmetry, horizontal glass, and slim stiles, and are frequently specified in darker frames — the black steel exterior door look is a common companion to this style. Traditional exterior doors use raised panels, decorative glass, and often sidelights, and are the most common configuration in replacement work.
Glass and panel configurations
- Half window exterior door — glass occupies roughly the upper half of the door; good light without full exposure.
- Metal exterior door with window — steel or aluminum frame with an insulated glass unit; common in modern and commercial-residential work.
- Exterior door with blind — an integral blind sealed between the glass panes, useful where privacy matters and no exterior shading is available.
- Metal and glass exterior doors — full-glass or large-lite designs in aluminum or steel; strong visual impact but higher solar gain and condensation risk in cold climates.
- Double exterior doors fiberglass — a pair of fiberglass leaves, often used at patio or grand entry locations; fiberglass resists denting and swelling better than wood in wet climates.
Where to Buy Wholesale and Discount Exterior Doors
Wholesale exterior doors are sold through three main channels: factory-direct supply, building-material distributors, and discount or surplus sellers. Each has a different risk profile.
Factory-direct supply gives you the widest control over size, color, glass, and hardware, and it is the channel that can actually deliver a true custom size rather than a “closest stock” compromise. The trade-off is that you deal with production lead times and minimum order quantities rather than same-week pickup. Distributors carry stock and offer local returns, but their size and finish range is limited to what they inventory. Discount and surplus sellers move overstock and discontinued lines at low prices, but sizes are unpredictable and matching a second order later is often impossible — a real problem on multi-unit projects.
When evaluating any wholesale channel, ask for four documents before committing: a dimensioned shop drawing, a glass and hardware specification sheet, a finish and warranty statement, and a packing list format. A supplier who cannot produce these is not set up for project supply.
For buyers comparing quotes, the useful comparison is not price per door alone but price per installed opening — including frame, hardware prep, glass, finish, and the cost of correcting a wrong size. A cheap door in the wrong rough opening is the most expensive door on the project.
Matching Supply to Project Requirements
Once sizing and style are settled, the remaining decisions are commercial and technical: can the supplier adjust the profile and fittings to local building codes, and can they document the shipment for customs clearance? These are the points where a factory-direct relationship earns its keep.
As a manufacturer, our approach at Jusen Door and Windows is to treat the buyer’s door schedule as the starting document. We build solid wood, thermal-break aluminum, and system doors and windows to the sizes on that schedule, with adjustable profile structures and fittings so the unit matches the target market’s building code rather than forcing the buyer to adapt a stock size. Customization covers size, color, glass, and hardware accessories, which is what makes non-standard items like a 32 x 78 replacement door or an arched entry feasible at wholesale volume rather than as a one-off.
Before shipment, units go through air-tightness, water-tightness, and wind-resistance testing as part of pre-shipment inspection, and export documentation — packing list, proforma invoice, and full customs papers — is prepared as standard. We ship both FCL and LCL direct from the factory, so buyers running a single-villa project and buyers running a multi-phase development can both be served without a middleman markup layered on top. If you are working from a door schedule and want a quote against your actual sizes and finishes, send us your requirements and we will respond with dimensions and pricing.
Common sizing and buying questions
What does 32 x 79 mean for an exterior door?
It is the nominal width and height in inches: 32 inches wide, 79 inches tall. The actual slab is about 31.5 x 78.5 inches, and the rough opening is typically around 34 x 80.5 inches for a prehung unit.
Where can I buy a 32×78 exterior door?
A 78-inch height is usually not a stock SKU, so the practical route is a factory or supplier that offers custom sizing. Confirm whether they quote nominal or actual dimensions before ordering.
What are the standard sizes for exterior doors?
The most common nominal sizes are 30, 32, 34, and 36 inches wide, with heights of 78, 79, and 80 inches. New construction typically uses 36 x 80; replacement work often uses 32 or 34 widths.
How do I measure for an exterior door with side lights or side panels?
Measure the full assembled unit width — door leaf plus both glass panels plus frame — and the total height from finished floor to head, then calculate the rough opening from that unit width rather than the door leaf alone.
Are wholesale exterior doors available in custom sizes and colors?
Yes, from factory-direct suppliers. Custom sizing, color matching, glass selection, and hardware specification are standard capabilities at the manufacturing level, though minimum order quantities and lead times apply.
What is the rough opening for a 32 x 79 exterior door?
Approximately 34 inches wide by 80.5 inches high for a typical prehung unit. Always confirm against the supplier’s shop drawing, since frame thickness and sill design change the figure.
Can I get a white exterior door with a blind or half window?
Yes. Integral blinds sealed between glass panes and half-window lite configurations are both available in factory-finished white, and specifying them together is a normal custom order rather than a special exception.
