I have several of these gates in my home.  They fit my standard doorways with no problems.  I have a bit wider opening in one area which has some higher moldings and it has to be placed above that molding to stay put which then puts it above the floor about 3 inches.  If you have a toddler that is adventurous they could crawl under it.  I do like how easy the locking mechanism is on these gates.  I can hold my newborn while installing the gate for my year and a half old.