Content Menu
● 1. Why Door Sizes Matter in 2026
● 2. Standard Interior Door Sizes
● 3. Standard Exterior Door Sizes
● 4. Standard Commercial Door Sizes
● 5. Specialized Door Types and Sizes
● 6. Door Size Standards by Region
● 7. How to Measure Door Openings Correctly
● 8. Building Codes and Compliance (2026 Update)
● 9. Door Sizing for Aluminum Doors and Window Walls
● 10. How to Evaluate Door Manufacturers
● 11. How We Meet These Standards at Jusen Door and Windows Manufacturing Co., Ltd.
● 12. Frequently Asked Questions
14 min read
A contractor in Phoenix ordered forty 36-inch pre-hung doors for a multifamily project. When the units arrived, the rough openings measured 35.5 inches — framed tight by a crew that “knew what they were doing.” Every single jamb had to be shaved, and the installation timeline doubled.
That is the reality of door sizing. One inch in the wrong direction costs days, not hours. This guide covers the dimensions that matter for interior, exterior, and commercial projects in 2026, plus the code requirements and procurement considerations B2B buyers need before placing an order.
Why Door Sizes Matter in 2026
Building codes are tightening. The Americans with Disabilities Act (ADA) clear width requirements, International Building Code (IBC) egress rules, and energy performance standards all influence what size door you can install — and where.
For B2B buyers, the stakes are higher than for a homeowner. A specification error on a 200-unit development means 200 rework orders. Permit delays. Penalty clauses. Relationships strained with general contractors.
This guide serves as a reference for architects, contractors, developers, importers, and distributors who need accurate dimensional data and the reasoning behind it.
Standard Interior Door Sizes
The standard US interior door is 32 inches wide by 80 inches tall, with 30-inch and 28-inch widths commonly used for bathrooms and closets. Door slab thickness is typically 1⅜ inches (35 mm). Metric markets standardize around 80 cm widths and 200–210 cm heights.
Common Interior Door Widths
The US and Canadian market recognizes several standard interior widths:
| Width (inches) | Typical Use |
|---|---|
| 24″ | Utility closets, small storage |
| 28″ | Bathrooms, secondary closets |
| 30″ | Bedrooms, bathrooms |
| 32″ | Most common for main bedrooms |
| 36″ | ADA-compliant accessible routes |
ADA guidelines require a minimum 32-inch clear opening width. Because the door slab itself takes up space when open, a 32-inch clear opening typically requires a 36-inch door leaf.
Standard Interior Door Heights
Eighty inches (6’8″) remains the default. But 84-inch (7’0″) doors are gaining ground in new construction — buyers want the taller proportion, and manufacturers have responded with more stock options. For luxury projects, 96-inch (8’0″) doors appear regularly.
Height affects cost more than width. Taller slabs require more material, larger hinges to handle the added weight, and careful handling during shipping.
Rough Openings for Interior Doors
For a pre-hung interior door, the rough opening formula is straightforward:
- Width: door width + 2 inches
- Height: door height + 2 inches
So a 32″ × 80″ door requires a 34″ × 82″ rough opening. The extra space allows for shimming, leveling, and ensuring the unit sits square.
Jamb width matters too. A standard 2×4 wall with drywall needs a 4-9/16″ jamb. A 2×6 wall needs 6-9/16″. Ordering the wrong jamb width creates gaps that require trim workarounds.
Metric Interior Door Standards
For buyers sourcing from or selling into metric markets, the common dimensions are:
- Widths: 70, 80, 85, 90 cm
- Heights: 200, 210, 220 cm
A European 80 cm door converts to roughly 31.5 inches — close to but not identical with the US 32-inch standard. Importers must be explicit about which system they are using. A “standard” door means different things in different markets.
Standard Exterior Door Sizes
The standard US residential exterior door is 36 inches wide by 80 inches tall. Double-door configurations commonly total 60, 64, or 72 inches in width. Exterior door slabs are thicker than interior ones — typically 1¾ inches (44 mm).
Residential Exterior Door Widths
Thirty-six inches dominates new construction. It accommodates furniture, meets accessibility guidelines, and has become the default expectation among homebuyers.
Older homes often have 32-inch or 34-inch exterior doors. Secondary entries — side doors, garage-to-house connections — may use 30-inch widths.
For double doors (French or patio configurations), common total widths include:
| Configuration | Total Width |
|---|---|
| 2 × 30″ | 60″ |
| 2 × 32″ | 64″ |
| 2 × 36″ | 72″ |
Exterior Door Heights
Eighty inches is standard. Eighty-four and 96-inch heights appear in custom and luxury construction. The 2026 trend leans toward 8-foot doors in premium builds — they make entryways feel more substantial.
One imperfect insight worth noting: taller exterior doors are not always better. They weigh more, require stronger hinges, and can be harder to seal against air and water infiltration. The aesthetic gain must be weighed against the performance trade-off.
Exterior Door Thickness and Performance
Exterior door slabs are 1¾ inches thick (44 mm) for solid wood, fiberglass, and steel units. This added thickness provides structural rigidity, space for insulation, and compatibility with heavier hardware.
For thermal-break aluminum entrance doors, frame depths typically range from 50 to 80 mm. The frame depth affects the U-value (thermal transmittance) and determines what glazing options fit.
Rough Opening for Exterior Doors
The formula shifts slightly for exterior doors because of the threshold:
- Width: door width + 2 inches
- Height: door height + 2.5 inches
A 36″ × 80″ exterior door needs a 38″ × 82.5″ rough opening. The extra half-inch in height accommodates the threshold and allows for adjustments to the finished floor height.
Exterior installation demands more care than interior. Flashing, shimming, and proper sealing are critical — water intrusion at the door opening is a leading cause of floor and subfloor damage.
Standard Commercial Door Sizes
The most common exterior commercial door configuration is 36 inches wide by 84 inches high for a single leaf, or 72 inches by 84 inches for double leaves. Interior commercial doors typically use 36-inch widths with 80-inch heights to meet accessibility requirements.
Commercial Door Widths
ADA requires a 32-inch minimum clear width for accessible routes. Because hardware and door stops reduce the clear opening, a 36-inch door leaf is the practical minimum for ADA compliance.
Common commercial widths run 36, 40, and 42 inches. High-traffic entrances often use double doors: 72 inches (2 × 36″) or 84 inches (2 × 42″).
Storefront aluminum entrance doors typically use 36 to 48 inches per leaf, depending on traffic volume and the structural capacity of the framing system.
Commercial Door Heights
Interior commercial doors usually match residential heights — 80 inches. Exterior commercial entrances commonly use 84 or 96 inches to match taller ceiling heights in lobbies and retail spaces.
Custom heights up to 120 inches appear in atriums and feature entrances, though these require engineered framing and specialized hardware.
What Is a Standard Exterior Commercial Door Size?
The most common standard exterior commercial door size is 36″ × 84″ for a single leaf and 72″ × 84″ for a double-leaf configuration. Some applications use 80-inch heights, but 84 inches is preferred for exterior entrances to match the scale of commercial spaces.
Egress requirements from the IBC may affect sizing. Buildings with high occupant loads need wider total egress widths, which can mean more doors or wider leaves.
What Is the Rough Opening for a 36-Inch Commercial Door?
For a 36″ × 84″ commercial door, the standard rough opening is 38″ × 84.5″. The formula: add 2 inches to the width and 0.5 to 1 inch to the height.
Commercial frames differ from residential. Hollow metal frames are often welded or knock-down (KD) with fixed dimensions. Aluminum storefront frames use a different anchoring system. Always confirm the frame manufacturer’s rough opening requirements before framing.
Commercial Door Materials
Three material systems dominate commercial applications:
- Aluminum storefront and entrance systems — lightweight, corrosion-resistant, available with thermal breaks for energy efficiency
- Hollow metal frames and doors — maximum durability, fire ratings available, used in corridors and stairwells
- Glass-heavy configurations — modern facades with narrow aluminum framing and large glass panels
Specialized Door Types and Sizes
Sliding Doors
Sliding doors range from 60-inch patio units to 120-inch and wider multi-panel configurations for villa and commercial projects. Panel heights typically match standard door heights: 80, 84, or 96 inches.
Thermal-break aluminum sliding systems are commonly custom-sized. The track system, roller hardware, and glass weight all factor into maximum panel dimensions.
Folding (Bi-Fold) Doors
Bi-fold doors use individual panels of 24 to 36 inches wide. Total opening widths range from 8 to 20 feet. Heights extend from 80 to 120 inches.
Folding door hardware must handle significant weight. Each panel’s hinges and trolleys need capacity ratings that match the panel size and glazing weight.
Casement and French Doors
Casement doors use single leaves of 24 to 36 inches, or pairs up to 72 inches. French doors follow the same pattern: 60, 64, or 72 inches total width.
Are 26-Inch Doors Standard?
Yes, 26-inch doors are a recognized standard size, but they are uncommon in modern construction. They appear mostly in pre-1970s homes, small closets, utility rooms, and mobile homes.
A 26-inch door is not ADA-compliant and rarely specified for new projects. The replacement market still exists, but inventory is limited — most manufacturers produce them as special orders.
Custom and Oversized Doors
Full-height doors up to 120 inches require engineered solutions. Pivot doors — which rotate on a vertical axis rather than swinging on hinges — allow for very wide and heavy leaves.
For importers, non-standard sizes require clear communication with the factory about exact dimensions, tolerances, and testing requirements.
Door Size Standards by Region
| Region | System | Common Interior Width × Height | Common Exterior Width × Height |
|---|---|---|---|
| North America | Imperial | 32″ × 80″ | 36″ × 80″ |
| Europe / UK | Metric | 80 cm × 200–210 cm | 90 cm × 210 cm |
| Asia-Pacific | Metric | 80–90 cm × 200–210 cm | 90–100 cm × 210 cm |
| Middle East | Metric | 80–90 cm × 200–210 cm | 90–120 cm × 210–240 cm |
Code references differ by region. North America follows IBC, IRC, and ADA. Europe uses EN 14351-1 for performance standards. Buyers must verify local codes before ordering — a door that passes in one jurisdiction may fail inspection in another.
How to Measure Door Openings Correctly
Measuring an Existing Door (Retrofit)
Measure the frame, not the slab. Take width measurements at three points — top, middle, bottom — and use the narrowest. Measure height at both sides. Measure wall thickness at the frame.
Check for out-of-square conditions. If the opening is racked or twisted, a pre-hung door will not fit properly regardless of size.
Measuring a New Rough Opening
The rough opening is the framed opening before the door unit is installed. Measure from stud to stud for width, and from the subfloor to the header for height.
Common mistakes include forgetting to account for subfloor height and ignoring threshold requirements. The finished floor height affects how the door unit sits.
Building Codes and Compliance (2026 Update)
IBC Requirements
The IBC requires a minimum 32-inch clear width for egress doors. There is no code limit on door leaf height, but practical constraints — hardware capacity, shipping limitations, structural support — apply.
Fire door assemblies must carry appropriate labels. NFPA 80 governs the installation and maintenance of fire doors, including size limitations for labeled assemblies.
ADA Accessibility Guidelines
ADA requires 32-inch minimum clear width, measured from the face of the door to the stop. Maneuvering clearance at doorways depends on approach direction and door swing.
Threshold height is limited to ½ inch maximum, with beveled edges required above ¼ inch.
Energy Codes
The International Energy Conservation Code (IECC) sets U-factor requirements by climate zone. For exterior doors, this drives decisions about glazing, insulation, and frame materials.
Thermal-break aluminum doors and insulated door systems help meet these requirements. Air infiltration and water penetration testing — referenced in standards like ASTM E283 and E331 — validate performance.
Door Sizing for Aluminum Doors and Window Walls
System Overview
Thermal-break aluminum doors use a polyamide strip to separate interior and exterior aluminum profiles, reducing thermal transfer. This construction is standard for energy-efficient commercial and residential projects.
Slim-frame systems achieve visible frame widths of 20 to 50 mm, maximizing glass area for aesthetic appeal.
Size Limitations and Structural Considerations
Aluminum door leaves have practical size limits based on wind load, deflection, and hardware capacity. Large panels require thicker glass and more robust framing.
Glass thickness requirements scale with panel size. A 36-inch door leaf might use 5/16″ glass; a 48-inch leaf may require ½” or thicker.
Hardware weight limits matter. Multi-point locking systems add security but also add weight and complexity.
Standard vs. Custom Sizing
Standard modules reduce cost and lead time because profiles are pre-extruded and hardware is pre-engineered. Custom sizes require additional engineering, testing, and potentially new extrusion dies.
Buyers should evaluate whether a project truly needs custom sizes or whether a standard module can be adapted.
How to Evaluate Door Manufacturers
When sourcing doors — standard or custom — the evaluation framework goes beyond price per unit.
Key Specifications to Verify
- Material specification: What alloy, what finish, what thermal break?
- Testing standards: Air-tightness, water-tightness, wind load — ask for test reports
- Certifications: Does the factory hold relevant certifications for your target market?
- Tolerance data: What manufacturing tolerances does the factory guarantee?
Questions to Ask Before Ordering
- What is the MOQ for standard and custom sizes?
- What is the lead time for each?
- What testing and certification documentation can you provide?
- How will the doors be packaged for ocean freight — FCL or LCL?
- Can you provide packing lists, proforma invoices, and customs documentation?
- How do you handle pre-shipment inspection?
Red Flags to Avoid
- Vague test data: A factory that cannot produce test reports for air and water tightness may not be testing at all
- Overpromising on tolerances: Real manufacturing has tolerance ranges; a factory that claims perfection is not being honest
- Unwillingness to document: Export documentation is not optional — a factory that hesitates on paperwork will cause customs delays
Choose A If… Choose B If…
- Choose standard sizes if: Your project has typical openings, timeline is tight, and budget is constrained. Stock doors ship faster and cost less.
- Choose custom sizes if: Your project involves renovations of older buildings, architecturally distinctive openings, or brand-specific design requirements. Custom doors require longer lead times but fit correctly.
How We Meet These Standards at Jusen Door and Windows Manufacturing Co., Ltd.
Understanding the standards is step one. Here is how we, as a door and window manufacturer, apply them in practice.
Customization Across Size Systems
Our factory produces solid wood doors, thermal-break aluminum doors and windows, system windows, casement doors, sliding doors, custom villa doors and windows, sunrooms, and aluminum alloy entrance doors. We fully customize sizes, colors, glass configurations, and hardware accessories.
Whether your project requires US-standard 36″ × 80″ doors, metric sizes for EU and Asian markets, or fully custom dimensions, we work directly with architects and contractors to match project-specific rough openings and code requirements.
Factory-Direct Supply with Quality Assurance
As a direct manufacturer, we supply without middleman markup — a structural advantage for B2B buyers managing project budgets. Every shipment undergoes strict pre-shipment inspection covering air-tightness, water-tightness, and wind resistance testing, aligned with the performance expectations discussed earlier in this guide.
Code Adaptability and Export Support
Our profile structures and fittings are adjustable to comply with local building codes in your target market — whether that means IBC and ADA in North America, EN standards in Europe, or other regional regulations. We provide full customs documentation, packing lists, and proforma invoices for smooth international logistics. FCL and LCL shipments deliver directly from our China factory.
Contact Our Team
Need doors manufactured to your market’s exact standard sizes? Contact Leon Wu at cyxs001@gmail.com or reach out via WhatsApp to discuss your project requirements with our factory team. We welcome OEM, ODM, private label, and bulk construction supply inquiries.
Frequently Asked Questions
What is the difference between a door slab and a pre-hung door?
A door slab is just the door panel — no frame, hinges, or hardware. It works when replacing a door in an existing sound frame. A pre-hung door arrives with the slab mounted on jambs with hinges installed, ready to set into a rough opening. Pre-hung units are easier to install and ensure proper alignment; slabs are more economical when the frame is reusable.
How much clearance should I leave around a door for installation?
For a pre-hung door, the rough opening should be about 1 inch wider and 0.5 to 1 inch taller than the door unit dimensions. This allows for shimming and leveling. For the door slab itself, leave approximately ⅛ inch clearance on each side and top, and ⅜ to ½ inch at the bottom for flooring and threshold clearance.
What is the most common exterior door width for residential homes?
Thirty-six inches (3 feet) is the standard. It accommodates furniture movement, meets accessibility guidelines, and is the default for new construction. Older homes may have 32-inch or 34-inch exterior doors. Double-door configurations most commonly total 60 inches (2 × 30″) or 72 inches (2 × 36″).
How does door height affect cost?
Taller doors cost more because they require more material and heavier hardware. An 84-inch door may cost 15–20% more than the equivalent 80-inch door. The hinges must handle additional weight, and shipping costs rise with package dimensions. For projects with many doors, the height difference compounds quickly.
Can a 36-inch door fit in a 34-inch rough opening?
No. A 36-inch pre-hung door requires approximately a 38-inch rough opening width. Attempting to force a door into an undersized opening causes binding, poor sealing, and long-term operational problems. If the framing is already in place and undersized, options include custom-sizing the door to fit or reframing the opening — both carry cost implications.
Final Considerations for 2026 Projects
Door sizing is not glamorous work. But it is foundational. A door that does not fit, does not meet code, or fails performance testing becomes a problem that touches every downstream trade.
Standard sizes exist for a reason: they balance cost, availability, and performance. Custom sizes exist for a reason too: buildings are not always standard, and design intent sometimes requires deviation.
The key is knowing which situation you are in — and asking the right questions before you order, not after the shipment arrives.
References
- International Code Council. (2024). International Building Code. https://www.iccsafe.org/products-and-services/i-code-2024/
- U.S. Department of Justice. (2010). ADA Standards for Accessible Design. https://www.ada.gov/law-and-regs/design-standards/
- National Fire Protection Association. (2022). NFPA 80: Standard for Fire Doors and Other Opening Protectives. https://www.nfpa.org/codes-and-standards/all-codes-and-standards/list-of-codes-and-standards/detail?code=80
- European Committee for Standardization. (2016). EN 14351-1:2006+A2:2016 — Windows and doors — Product standard, performance characteristics. https://standards.cen.eu/
- International Code Council. (2021). International Energy Conservation Code. https://www.iccsafe.org/products-and-services/i-code-2021/
- ASTM International. (2019). ASTM E283 — Standard Test Method for Determining Rate of Air Leakage Through Exterior Windows, Skylights, Curtain Walls, and Doors Under Specified Pressure Differences Across the Specimen. https://www.astm.org/e0283-19.html
- ASTM International. (2019). ASTM E331 — Standard Test Method for Water Penetration of Exterior Windows, Skylights, Doors, and Curtain Walls by Uniform Static Air Pressure Difference. https://www.astm.org/e0331-00r09.html
