Panel height: pick this first
- 24 inches — toy breeds and young puppies only. A medium dog steps over it, and even a puppy will outgrow it within months. Buy it for a chihuahua or for a very short-term puppy phase, not as a general-purpose pen.
- 30 inches — the compromise. Fine for small dogs and calm medium ones.
- 36 inches — the sensible default for anything medium, and the height most people should buy. It is tall enough that a dog has to genuinely commit rather than casually stepping over.
The honest caveat: no pen height contains a dog that decides to climb or jump. A determined dog gets out of any of these, and a pen is not the right tool for that dog — a crate or a properly dog-proofed room is.
Eight panels, not six
Panel count sets both the enclosed area and the shapes available. Eight panels give you a usable square or octagon; six give you something noticeably cramped once a bed and a water bowl are in it.
Eight also unlocks the more useful configurations. A pen does not have to be a closed shape — you can run it as a barrier across an alcove, or fold it into an L to block a corner of a room, or open it out as a room divider. Several manufacturers sell add-on panel sets, which is worth checking if you think you might want a bigger footprint later.
The door question
A walk-through door sounds like a luxury and is not. Without one, every interaction involves lifting the dog in and out over the top — awkward with a medium dog, unpleasant with a heavy one, and a nuisance forty times a day with a puppy.
Check the latch as well as the door. Simple drop-pin latches are the norm and most are fine, but a nose-operable catch on a smart dog is a pen that opens itself. And check the door swing direction works for where you plan to put it.
Stopping it walking across the floor
The classic pen failure is not escape, it is migration: the dog leans on one side, the whole pen slides, and over an afternoon it has traveled three feet across a hard floor and squashed itself against a wall.
Three fixes. Most pens include ground stakes for outdoor use — useless indoors. Indoors, put the pen on a rug or an interlocking foam mat, which adds friction and protects the floor. Or anchor one side against a wall or a heavy piece of furniture so it cannot travel. Non-slip feet are worth looking for; not many pens have them.
What a pen is not
It is not a roof, so a climber gets out and a jumper gets out. It is not house training on its own — a pen large enough to toilet in one corner and sleep in another removes the pressure that makes crate training work, so for house training specifically a correctly sized crate does more.
And it is not a substitute for supervision over long periods. Guidance on crate and confinement training consistently frames confinement as management for reasonable periods rather than a way to leave a dog for a working day. A pen gives a dog more room than a crate; it does not change how long it is fair to leave it.
Setting it up so it works
Put a bed at one end and water at the other, with something to chew in between. Introduce it the same way you would a crate — short periods with something good happening, while you are in the room, before you ever leave it. And site it where the household is, so the dog is contained but not isolated. A pen in an empty room teaches a dog that being penned means being left, which is the opposite of what you want.
