My door is 50.5" and it fot perfectly with the long extender piece. Didnt have to use both extenders. I recommend having 2 ppl available to place it as it can be a little tricky. Everything slides together. It is nice and tall. Im 5'2 and bought this to keep my baby out of the kitchen and it comes above my belly button. Way its designed baby cant stick head through rails or climb it. Since i have a cat that cant jump over gate bc its too fat too i had to raise gate off ground. Its still just as sturdy as if on ground and baby cant get underneath. Highly recommended product