Standard Door Dimensions: Sizes for Residential & Commercial

Last updated: September 19, 2026

What Are Standard Door Dimensions?

The dimensions of a door are its width, height, and thickness. In the United States, the most common standard door size is 36 inches wide by 80 inches high (3’0″ × 6’8″), with 32 inches × 80 inches used widely for interior rooms and 30 inches × 80 inches for bathrooms and closets. Thickness is typically 1⅜ inches for interior doors and 1¾ inches for exterior doors. These are nominal slab sizes — the finished opening is larger once the frame and clearance are added.

That single answer covers most residential work, but it is not the whole picture. A buyer specifying doors for a project needs three numbers per opening: the door slab, the frame, and the rough opening. Confusing them is one of the most common and expensive mistakes in door procurement, because a door ordered to the wrong reference point cannot be corrected on site.

Why standard sizes exist

Standardization is a manufacturing and logistics decision as much as a construction one. Fixed slab sizes let factories run common tooling, hold inventory, and ship faster. They also let builders frame openings before doors are selected. When a project stays inside standard sizes, cost and lead time drop. When it moves outside them, every door becomes a custom item with its own drawing, mold, and inspection.

The three measurements that matter

Width and height get most of the attention, but thickness and frame type determine whether a door actually fits. A 36-inch slab in a thin jamb and a 36-inch slab in a heavy exterior frame produce different rough openings. Buyers who understand this distinction can read a schedule, check a quote, and catch errors before production starts.

Standard Door Size Chart (Inches, Feet, Centimeters)

The table below covers the sizes most commonly specified in residential and light commercial projects. Treat these as common industry ranges, not universal rules — regional codes and individual manufacturers vary.

A few notes on reading this table:

• Width is measured across the slab face, not the opening.
• Height is the slab height, measured from the bottom edge to the top edge.
• Metric values are rounded to the nearest centimeter; European and Asian manufacturers often work in clean metric modules instead (see regional differences below).
• Taller doors — 96 inches (8’0″, 244 cm) — are increasingly common in higher-end residential work and in commercial entries.

Interior vs. Exterior Door Dimensions

Interior and exterior doors follow different rules because they do different jobs.

Interior doors are lighter, thinner, and sized for circulation rather than security. The standard interior door is 80 inches high and 24–36 inches wide. Bathrooms and closets typically take the narrow end of that range; main bedroom and living-area doors take the wide end. Interior thickness is usually 1⅜ inches, though heavier solid-core doors may run 1¾ inches.

Exterior doors are built to resist weather, forced entry, and wind load. Standard exterior door dimensions are 36 inches × 80 inches for a single entry, with 1¾-inch thickness as the norm. Wider entries — 42 inches or double-door configurations — are common on main façades and commercial fronts. Exterior doors also carry a raised threshold, which reduces the usable clear height inside the frame.

The practical consequence: an exterior door and an interior door of the same nominal width do not share the same rough opening. If a project swaps one for the other, the framing must change.

For a deeper look at how exterior sizes are specified, see this guide to standard exterior door dimensions.

Bedroom and Sliding Door Sizes

Bedroom doors

The standard bedroom door size is 32 inches wide by 80 inches high, with 30 inches and 36 inches as the common alternatives. A 32-inch door is wide enough for furniture and everyday movement without consuming wall space; a 36-inch door is preferred in larger primary bedrooms and where accessibility matters.

When buyers ask what size door a bedroom needs, the honest answer is: it depends on the swing clearance and the wall return. A 36-inch door needs a longer wall segment to open against. In tight layouts, a 30-inch or 32-inch door is often the better decision even though 36 inches is nominally “standard.”

Sliding doors

Sliding doors are specified per panel, not per opening. Standard sliding door panel dimensions are 30–36 inches wide by 80 inches high, with a 1¾-inch thickness for exterior units. A two-panel slider therefore covers a rough opening of roughly 60–72 inches; a three-panel unit scales accordingly. Because panels overlap at the meeting stile, the total opening is slightly less than the sum of panel widths.

Sliding configurations are also where custom sizing shows up most often, since opening widths are dictated by the wall rather than by a standard module. If your project involves a wide opening, this overview of sliding French doors explains how panel counts and sizes are matched to the space.

Door Framing and Rough Opening Dimensions

Rough opening dimensions are the framed gap in the wall before the door unit is installed. They are always larger than the door slab, because the frame, jamb, shims, and clearance all sit inside that gap.

A widely used starting rule for a single door is:

• Rough opening width = door slab width + 2 inches
• Rough opening height = door slab height + 2½ inches

So a 32-inch × 80-inch door typically needs a rough opening of about 34 inches × 82½ inches. This is a starting point, not a universal formula. The actual figure depends on jamb thickness, whether the unit ships pre-hung or as a slab, and the manufacturer’s installation detail. Pre-hung units often come with their own published rough opening, which should always take precedence over a generic rule.

Two risks worth flagging:

• Fire-rated doors have separate code requirements for dimensions and clearances, and they should never be sized from a general residential rule.
• Accessible routes have minimum clear width requirements that vary by jurisdiction and by which code edition applies. A common design target is a 32-inch minimum clear opening, but this is not a universal legal figure — confirm the applicable local code before finalizing a schedule.

Terms buyers should know

How to Measure for a Door

Measuring for a replacement is different from measuring for a new opening, and mixing the two up causes most ordering mistakes.

Replacing a door in an existing frame:

• Measure the slab width at three points — top, middle, and bottom — and use the smallest figure. Old openings are rarely perfectly square.
• Measure the slab height on both sides and use the smaller figure.
• Measure thickness at the hinge edge.
• Note the hinge positions and swing direction; a replacement slab must match the existing mortises or the frame must be reworked.

Framing a new rough opening:

• Start from the finished door size you want, not the wall gap.
• Add the frame and clearance allowance per the manufacturer’s detail.
• Confirm the rough opening width, height, and diagonal squareness before the wall is closed.
• Verify the wall is thick enough for the jamb depth, especially in exterior walls with insulation and cladding.

A single wrong measurement at step 1 or 2 can turn a standard order into a custom one. It is worth the extra ten minutes.

Regional Variations in Door Sizes

Door sizes are not globally standardized, and international buyers should never assume a US schedule will translate directly.

• United States and Canada: imperial modules dominate — 32 in × 80 in and 36 in × 80 in for residential, with 1¾-inch exterior thickness. Rough openings are usually quoted in inches.
• Europe and the UK: metric modules dominate. Common interior sizes cluster around 60–90 cm wide by 200–210 cm high, with the UK using its own historical imperial-derived sizes that do not match US modules. Frame and leaf are often specified separately in metric.
• Asia and the Middle East: practice varies widely by market. Some countries follow European metric modules, others follow local conventions, and imported project work often specifies to the destination country’s code rather than the manufacturer’s default.

The practical takeaway for anyone sourcing internationally: specify the destination standard, not the production standard. A door that is standard in one market may be a custom item in another, with the cost and lead-time implications that follow.

Custom Door Sizing and Manufacturing Considerations

Standard sizes cover most residential openings, but commercial projects, villa work, and renovation jobs frequently fall outside them. When that happens, the buyer is no longer choosing a size — they are commissioning one.

Three factors drive the decision:

• Opening geometry. Non-standard wall heights, wide sliding spans, and arched or angled openings cannot be met with a catalog size.
• Local building codes. Wind load, thermal performance, and accessibility requirements differ by market, and they can force a specific profile or fitting rather than a specific size.
• Project logistics. Custom doors need drawings approved before production, which adds lead time. Ordering early matters more than ordering cheaply.

This is where working directly with a manufacturer rather than a trading intermediary changes the process. As a factory, our approach is to treat the destination market’s building code as the starting point: the profile structure and fittings are adjusted to match local requirements, and sizes are produced to the project’s own schedule rather than rounded to the nearest catalog module. Buyers can specify full customization on size, color, glass, and hardware, and receive the packing list, proforma invoice, and customs documentation that international shipments require. Every unit is inspected before shipment for air-tightness, water-tightness, and wind resistance, and orders ship FCL or LCL direct from the factory.

If your project involves non-standard openings or a market with specific code requirements, Talk to Our Team with your opening schedule and destination country, and we can confirm what is standard, what needs to be custom, and what the framing allowance should be.

In short: a door is a movable barrier defined by width, height, and thickness, and its standard dimensions vary by type and region. In the US, the common residential standard is 32 or 36 inches wide by 80 inches high, with exterior doors typically 36 inches × 80 inches and 1¾ inches thick. Rough openings are always larger than the slab, typically by about 2 inches in width and 2½ inches in height for a single door. Metric markets use different modules, so international buyers should specify to the destination standard. Where standard sizes do not fit, custom manufacturing is the practical route — and it starts with an accurate opening measurement.

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