It seems I meet a dozen people a day that ask me if Millie is a teacup pig or flat out state they are looking to get a teacup pig. And I'm quick to point them in the right direction to finding one. You just go to the pet store, walk past the Unicorn babies, and you should see all the teacup piglets that are free to a good home. My guess is that the average weight of a full grown 'teacup' piglet is around 100-150 pounds. And the more someone pays for a teacup piglet and the smaller the size they are promised, the larger the pig will likely end up.
Yes, teacup pigs are not real. There is no pig that will fit in a teacup when full grown. Based on my research, discussion with people working at rescues and the brilliant resource, Mini Pig Info, pigs under 50 pounds when full grown are typically unhealthy or malnourished. Sure, there will always be the exception, just as there is the occasional human that won't grow past 3 feet tall. But, typically bad breeding practices (over inbreeding leading to genetic disorders) and underfeeding is the most likely reason a pig stays under 50 pounds. So, if you are looking into getting a pig and require that it be a teacup pig, please don't adopt a pig. Rescues are full of 150 pound teacup pigs that are abandoned the minute their parents realize they are a living being that needs love and care regardless of how big they will get.
But, if you are simply looking to adopt a mini pig, should size matter? Only if you have special circumstances in your living situation that make having a larger pig too difficult. Just as some people can fit a cocker spaniel sized dog in their home but not a St. Bernard, some people may be able to home a 100 pound pig but not a 250 pound pig. Otherwise, any sized pig can make a loving house mate. All pigs, regardless of size can make messes, can be destructive and can pose a whole assortment of challenges. But, in terms of the loving, intelligent qualities that make pigs so wonderful to be around, a 600 pound pig like Esther the Wonder pig is no different than our 75 pound Pumpkin. So, if you have a decent size yard and a house that is not overly tiny, the size of the pig you adopt should matter less than the connection you feel with the pig when you visit a rescue to meet the potential pigs for becoming a new member of your family.
Our situation is a bit unique in that we live in a two bedroom condo on the second floor. And there is no way to build a ramp down our winding stairs. So, the only way I can get our pigs in and out is by carrying them down. So, this is something to consider if you live in a situation where stairs are required for getting pigs in and out of the house. Pigs do not like stairs and it can lead to an early onset of arthritis. Again, this is another reason no one should ever buy a piglet. You have no guarantee regarding the size of your pig. And even if a breeder promises to take the pig back, that likely means an unhappy ending for that pig. Rescues or rehoming requests online are the only place anyone should ever get a pig. This will ensure that less pigs end up in rescues, on craigslist or worse euthanized or sadly even in backyard BBQs (yes, this actually happens more often than you'd imagine). Now, my family will do whatever it takes to ensure Millie, Charlotte and Pumpkin spend their lives with us. So, if any of our pigs end up bigger than I can carry, we will move (and have been looking into this just to make life easier for us). But, Pumpkin was a former breeder pig and needed a home and didn't want her to end up euthanized or continuing to be used as a breeder. So, we have made life with pigs in a condo work (Charlotte is her daughter and we asked to keep one of her babies with her when we adopted Pumpkin).
The reality of pigs is, most pigs will be 100-150 pounds. And in most condo and apartment situations, this will not work or not be allowed by the rules of the complex. That being said, if you live in a condo or apartment where pigs would be allowed and you are well informed about all the other factors that go into adopting a pig, we have found life with pigs in our condo to be one of the greatest choices we ever made. They have brightened our life more than we can express. Though, ideally, we'd live in a single family home with a private yard.
In conclusion, the size of a pig shouldn't matter in regards to the benefits your family will receive from having this amazing new family member. The pigs unfortunately abused by animal agriculture are every bit as loving, intelligent and amazing as the smallest pigs (as demonstrated by Esther the Wonder Pig). The only time size should be an issue is when you legally or logistically cannot have a larger pig in your home.