Free Tool · New 2026
Door Size Calculator (Standard Sizes Guide)
Enter your rough opening width and height to find the closest standard door size, plus a clearance check that's useful when planning a smart lock, video doorbell or access control reader on that door.
Want an exact number, not an estimate?
This calculator gives a strong planning estimate. For an exact, guaranteed figure, our engineers confirm everything during a free site survey.
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How this tool works
Enter your rough opening measurements and the tool matches you to the closest common standard door size used in the region. Standard sizing helps when ordering a replacement door, a smart lock retrofit kit, or planning an access-control reader, since off-standard openings often need a custom or made-to-measure door.
Planning a smart lock or access control reader on this door?
Beyond size, a few things matter for electronic hardware: door thickness (most smart locks need 35-55mm thickness), whether the door is solid or hollow-core (solid strongly recommended for main entrances carrying a smart lock), and enough flat stile width beside the existing lock for the new hardware's backset and reader housing.
Fitting a smart lock or video intercom to this door?
We handle smart lock and video intercom installation across Abu Dhabi, including confirming your specific door is compatible before ordering hardware.
Frequently asked questions
90 x 210 cm is a very common standard main entrance door size in this region, though villas often use wider entrance doors (100cm+) for a grander look.
Most solid-core doors of standard thickness (35-55mm) can be retrofitted, but hollow-core doors, very thick custom doors, or doors with unusual existing hardware may need an assessment first.
You'll likely need a custom or made-to-measure door - this is common in older villas or renovated openings, so measure carefully and share exact dimensions with your door supplier.
Yes, solid-core or metal doors are generally recommended for exterior entrances carrying smart locks or access-control readers, both for security and to properly support the hardware's drilling and mounting requirements.