Ok, you have a great cage (or have found the cage of your dreams). How many rats does it fit? Good question, and not one that everybody can agree with. My personal preference is 2 cubic feet of rat per cage, since I only keep males, and they tend to get rather, ahem, big. For females, who are generally smaller, I would recommend 1.5 cubic feet of space per rat. In cages of both sexes (properly spayed or neutered of course!), I would go with 2 cubic feet per rat.
Why cubic feet, and not square feet, as others recommend? Because rats are three dimensional. That's my staple argument. It's up to the owner to make the best use of the cage space available with litter pans, hammocks, balconies, tubes, etc.
So, how do you figure out how many rats can fit into a cage? Well, you can do it by hand, a calculator, or there are two cage size calculators which are just plug and chug.
By hand:
If you're working in inches, multiply the dimensions of the cage (in inches) (length x width x height), then divide by 3,456 for males, or 2,592 for females.
If you're working in centimeters, multiply the dimensions of the cage (in centimeters) (length x width x height), then divide by 56,633 for males, or 42,475 for females.
Pretty simple, huh? So, not working out right? Click on the Cage Calc link to the right for a rudimentary cage size calculator, or another, much prettier one, is located here, go to Odds & Ends, then cage size.
