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Code · ADA

Interior Door Size Selector

Interior doors aren’t one-size-fits-all. Bedrooms need a different width than bathrooms, ADA compliance adds clearance, and the rough opening for framing depends on the door slab. Pick the room type and accessibility need; the tool returns the door size, clear floor space, and rough opening dimensions.

Inputs

Door location & code
Available wall opening

What problem this solves

Designers specify doors by what looks right on a plan, but the door’s actual performance is determined by code. IRC requires a minimum 80 × 200 cm door for habitable rooms; ADA requires 90 × 210 cm with clear floor space. Getting either wrong means a building inspector fails the work, or a wheelchair user can’t enter the room. The calculator applies the right code level to the right room type.

Rough openings are the most common framing mistake. The slab (the door you buy) is smaller than the framed hole by exactly the thickness of the frame (about 5 cm width and 2 cm height, with some play). The framer needs to know the rough opening, not the slab size, to build the wall correctly. This tool returns both.

Who it’s for

Why code matters more than aesthetics

Code is the floor; aesthetics is the ceiling. An IRC-compliant 80 × 200 cm door is the legal minimum for bedrooms; you can go larger for proportion or accessibility, but not smaller. A bathroom door can be 70 × 200 cm under IRC but should be 80 cm for accessibility — the 70 cm door is grandfathered in existing homes but not in new builds in many jurisdictions.

Limitations

Practical rules of thumb

Bedrooms: 80 × 200 cm standard, 90 × 210 cm for accessibility. Bathrooms: 70 × 200 cm minimum under IRC, 80 cm preferred for accessibility. Closets: 60 × 200 cm minimum. Passage: 80 × 200 cm standard. Office: 80 × 200 cm standard, 90 cm if frequently receiving clients. Add 2.5 cm to slab width and 2 cm to slab height for the rough opening; add another 5 cm of clearance on the swing side for ADA clear floor space.

Common questions

What if my available wall opening is smaller than the recommended door?

You have three options: keep the door and accept a non-ADA-compliant narrow entry (often fine for existing homes under IRC); widen the opening (requires reframing, often adds 30+ cm of wall work); or use a different door type (sliding or pocket door uses the wall cavity, not the swing clearance).

What’s the difference between ADA and visitability?

ADA is the federal accessibility standard (US) for public buildings and is increasingly referenced in residential. Visitability is a lower-bar voluntary standard: at least one zero-step entry, a 80 cm door on the main floor, and a half bathroom on the main floor. It’s enough for a friend in a wheelchair to visit but not enough to live in full time.

Can a 70 cm bathroom door be grandfathered?

In existing homes, IRC allows the existing door size to remain. In new construction or renovations requiring a permit, the local jurisdiction often requires bringing the door up to current code (usually 80 cm). Check with your local building department.

What if I want a wider door for proportion?

Go wider — a 90 cm or 100 cm door in a tall ceiling feels appropriately scaled and improves daily use (carrying laundry baskets, moving furniture). The cost premium is small (a 90 cm slab is roughly 15% more than an 80 cm slab). The framing work is the bigger cost.

About this tool

The Interior Door Size Selector is one of 36 tools on InteriorLab. Code references come from the 2024 IRC and 2010 ADA Standards.

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Disclaimer

Code values are US-based; local jurisdictions may differ. Always verify with your local building department. See Disclaimer.