How Big Can Koi Fish Get?

Having koi fish in your home is a surefire way to brighten up your interior or exterior, as well as add a level of class to your dwelling. For this reason, many homeowners choose to have koi fish in their ponds or aquariums, due to their beauty, bright colors and sophistication. However, many would agree that the bigger their koi fish, the more impressive, and so they try to obtain the largest sized koi they can afford. But how big can koi fish get? Let us take a look at standard koi fish sizes, as well as some examples of large koi fish.

Standard Koi Fish Sizes

Generally, koi fish can be categorized by their size into various types. While domesticated fish tend to be on the smaller side for ease of care, accommodation, and feeding, some people do also keep larger fish if they are able. You will notice that the size of the koi fish once it reaches adulthood does actually depend on the type of koi, as mentioned below.

The normal, average koi fish will usually grow to around 12-15 inches long, or 1 foot minimum. Due to their relatively small size, these koi are best suited for home aquariums indoors. They look beautiful, are well complemented by a nicely decorated aquarium in the home, and as they do not need too much to eat, they are relatively easy to maintain. They also cost far less than the larger varieties of koi.

Japanese koi are a larger type of koi than the normal ones. They grow to around 22-26 inches in length, or around 2 feet long, and are quite sizeable – so much so that they would not fit in an indoor aquarium (unless you have a massive one). Japanese koi tend to be found in outdoor ponds where they can swim freely with more space. If one’s indoor pond is large enough, they could stay indoors too.

Then come the largest type of koi fish: the Jumbo Koi. Jumbo koi fish can grow up to 34-36 inches long, or a whopping 3 feet long. Due to their large size, they are usually only housed in sizeable outdoor ponds. Fun fact: The world’s largest koi carp ever in history is known as Big Girl, a gigantic koi 4.1 feet long and weighing in at 91 lbs. Big Girl is owned by Geoff Lawton in Wiltshire, England, and she eats a half kilo of pedigree food every day in order to maintain her body weight.

Koi Growth Rates

In general, a koi fish takes about 3 years to get to its maximum length. However, smaller types of koi do grow faster, potentially able to reach full size in 2 years or less.

Your average koi should reach about 8 inches in length after the first year, typically speaking. After that, your koi’s growth would depend on the type of koi and its typical growth rate, as well as factors such as pond temperature and size, water quality, nutrition, feeding schedule, and much more. If you’re looking for the best products to ensure your koi grows big and healthy, look no further than the Everything Koi shop for all your koi care needs!