how long does it take koi to grow to full size?
They usually don't get more than 15 inches but the largest types can be around 36 inches. They normally live for about 30 years but its not unusual for them to reach 100 if well cared for. The oldest koi was 226 when it died in the 1970s it can take more than 10 years to get to full size. Basically if you raise them the cheap American way, in a backyard pond or a mini pool at a Chinese restaurant, you can expect to keep them for about 30 years and get foot long fish.