How many goldfish can you keep in a 20 gallon tank? How about a 30 gallon tank? How much space do common/comet and fancy goldfish need? You’ll find the answers in our guide to goldfish tank size.
Of course, you’ll also need to know how big your own tank is. To check, use this handy calculator!
Enter the length, width and height of your tank into the calculator below and we’ll tell you your tank volume in gallons and litres. Plus how many common, comet or fancy goldfish you can keep in your tank!
We’ll also recommend a suitable filter for your tank size and let you know if your tank dimensions make it particularly important to add an air pump to your aquarium.
Our recommendations are based on a minimum tank size of 20 gallons for a single fancy goldfish and 30 gallons for a single common/comet goldfish.
Remember – if you have other fish in your goldfish tank, as well as goldfish, you will need to factor in the needs of your goldfish’s tank mates too.
Please enter the width, depth and height of your tank in the boxes above.