Most people expect rabbits to be small pets. They’ll bring home a baby rabbit and subsequently be surprised when the adult rabbit is the size of a small cat. Even dwarf and mini breeds of rabbits are bigger than most people expect. I regularly hear people exclaim at how big a Holland Lop is, for example, even though this is a very small breed of domestic rabbits.
The adult weight of an average-sized house rabbit is about 6 pounds. Dwarf and mini breeds of rabbits will usually be full grown at 4 pounds, while the giant breeds typically reach 10 to 15 pounds. The largest breed of rabbits can reach upwards of 20 pounds.
The misconceptions about the size of rabbits come from the size of wild rabbits. Many people, especially those who live in suburban and rural areas, have seen a wild rabbit at some point in their lives. People will understandably believe that this is simply the size that rabbits should be. However, wild rabbits are quite small compared to the typical house pet. Like many other animals, including cats and dogs, rabbits come in all different shapes and sizes.
The average size of adult rabbits
The average size rabbit you will see among house pets is about six pounds. However, this is about as useful as saying an average dog weighs 35 pounds. While it may give you a general mental picture to help you know what to expect, it won’t help you figure out the size your own rabbit will reach.
As you might expect, the size of rabbits can vary significantly depending on their age and breed. The size difference is not as drastic as you’ll see among breeds of dogs, but it’s not insignificant. Some rabbits can be quite small, while others are surprisingly large. Because of this, I will generally classify rabbits into three categories.
Small Rabbits (up to 5lbs)
Small rabbits encompass most of the dwarf and mini breeds. These are the rabbits whose maximum weight will never be more than five pounds. Believe it or not, this is actually the category with the fewest number of rabbit breeds. Of the 50 breeds recognized by the American Rabbit Breeders Association (ARBA), only 11 of them have a maximum weight under five pounds. However, you will disproportionately see these rabbits as house pets because most of the time these breeds are specifically bred to be pets.
Medium Rabbits (5-8lbs)
The most commonly seen breeds of rabbits are in the medium, or average-sized, category. These rabbits will reach an adult weight of anywhere between 5-8 pounds. Most rabbits will weigh in on the lower side of this range, at about five or six pounds. While small compared to many other rabbit breeds, this average size is still two to three times bigger than most people expect of a pet rabbit. There are about 15 breeds that would typically fall into the medium category. However, a small rabbit from one of the larger breeds may also fall under eight pounds.
Large rabbits (8lbs or more)
While large rabbits make up the majority of ARBA-recognized rabbit breeds, most of these breeds are rare and are not commonly seen as house pets. Rabbits in this category will typically grow to be anywhere from 8-15 pounds. Many of these larger breeds of rabbits have been developed as meat rabbits, rather than as pets. While they are being seen as pets more and more, it’s still not common to have one of these large rabbits as house pets.
How to know how big your rabbit will get
If you have a baby rabbit and your curious about how big the little bunny will get, there are a couple of ways to make a good estimate. This will help make sure you are prepared with a large enough enclosure by the time they reach their full adult weight.
The quickest way to get an estimate for how big your rabbit will get is by looking into their breed. You can check out my rabbit breed chart to find the range to expect for your rabbit if you happen to know what breed they are.
However, if you adopted your rabbit and don’t know what breed they are, you can still estimate their adult size. If you have an idea of your rabbit’s current age, you can use that as an indicator for their full grown weight. This is not an exact science, but it can give you a pretty good estimate so that you know what to expect.
When a rabbit is about 4 months old, they will be approximately half of their adult size. This means if you have a small rabbit who is only about 3 pounds, they will grow to be about 6 pounds when they are an adult.
When a rabbit is about 6-8 months old, they will be approximately ⅔ of their adult size. So if you adopted a rabbit who’s not a year old yet, but not quite a baby bunny, they’ll still grow a little. At this age, if your rabbit is 3 pounds, their adult weight will likely end up being about 4.5 pounds.
How to weigh your rabbit
With all this talk about size and weight, you may be wondering how to know what your rabbit weighs. At the vet, they’ll have a specialized scale for animals where they can place the rabbit and weigh them. If you want the exact weight of your rabbit, you can bring them in for an appointment. Your vet would also be able to tell you if your rabbit is overweight or underweight and help ensure your rabbit is healthy.
If you want to weigh your rabbit at home, there is an easier way. All you need is a standard scale that you probably already have in your bathroom. What you will need to do is:
- Step on the scale and weigh yourself. For example, say you weigh about 120lbs.
- Go pick up your rabbit and step on the scale again with the rabbit in your arms. To continue the example, say the two of you together weigh 126lbs.
- Now subtract your own weight from the weight of you and your rabbit to get the weight of your rabbit alone. In our example, this would mean (126lbs – 120lbs = 6lbs). You now know that your rabbit is 6lbs.
How long until a baby rabbit is full grown?
Most rabbits will reach their adult size around one year old. Some rabbits will continue to grow a small amount until they are a year and a half, but it will not be a significant increase in size after this point.
If your rabbit continues to gain a large amount of weight after this point, it is likely because they are overeating or eating too many unhealthy treats. You may need to consult your veterinarian about putting your rabbit on a healthy diet and helping them lose weight. Learn more about obesity in rabbits and what you can do to prevent it.
The largest breeds of rabbit
The largest breed of rabbit that is recognized by the ARBA is undeniably the Flemish Giant. If you’ve seen any of the heartwarming stories about giant house rabbits, it most likely featured one of these Flemish Giant rabbits. These rabbits typically grow to at least 15 pounds, but they’ll regularly reach a weight of 20-25 pounds as well.
Flemish Giant rabbits don’t really have a maximum weight though. The rabbit who holds the record for biggest in the world is a Flemish Giant, Ralph, who weighed in at a massive 55 pounds. He beat out Darius, the previous world record holder, who weighed 49 pounds.
While Flemish Giants are the only breed that regularly reaches more than 20 pounds, there are other giant breeds who are known to reach 12-15 pounds.
- Checkered Giants
- French lops
- Giant Chinchilla
- New Zealand
The smallest breeds of rabbit
The smallest breed of domestic rabbits is not as easy to identify. Many people will point to Netherland Dwarf rabbits, which are a very popular breed for keeping as pets because of their small size. These rabbits will typically only reach about 2lbs to 2.5lbs as adults.
There are a couple of other breeds that compare in size to Netherland dwarfs. The most notable are Britannia Petite rabbits. These rabbits also have a maximum adult weight of 2.5lbs and can weigh even less. However, they are not nearly as common since they were bred originally to be elegant show rabbits.
There are a handful of other small breeds of rabbits that regularly weigh less than 3 pounds.
- Dwarf Hotots
- Jersey Wooly
- “American Rabbit Breeders Association.” ARBA, https://arba.net/recognized-breeds.
- “Breed Research.” PetGuide.com, www.petguide.com/rabbit-breeds
- “Ralph, World’s Largest Bunny Rabbit, Weighs 55 Pounds And Eats $90 Of Food A Week.” HuffPost. April 2013, https://www.huffpost.com/entry/ralph-worlds-largest-bunny-rabbit_n_3006487.