Looking into getting a hamster and is needing a bit of help with chossing a cage....

[Wolfsi]

Yup, been looking into getting a dwarf hamster after I move in March and have been looking at cages, though I been having trouble finding a cage with a great size (450 +) that is affordable. So I started looking into Ikea DIY cages....

Right now I'm looking at the billy cage which would be
80x40x35cm which would be roughly 447 square inches when taking inside measurements into account.... so to small compared to the 450

So I been considering adding the smaller Billy bookshelf to extend the cage... it measures 40x40x35 cm so adding that would make it roughly 863 square inches if I got the math right.... would this make a great cage size???

The hight of a billy cage would be about 35 cm to 33 cm...

Also, what is the general opinion on using the billy cage when it comes to cleaning and keeping the cage over the years a hamster live?