The cage calculator doesn't include either how much rats get their free run time. If you only let them run half a hour a day

then they need a lot larger cage, when you let them run 6, or even 15 hours a day (i now let, because i am on holiday, 6 is usual.) then you can maybe even have one extra rat. What is strange- for two cubic feet, calculators give different answers.

My cage fits for 6 rats, i have 4.

What also very much disturbs me is, that for example, the calculator says 3 rats, it fits for 2, when calculator says 13, it fits for 14. (example only)

It's bit hard to explain, especially because my home language isn't English, but I'll try.

Rats don't use only their 2 cubic feet. They use all of the cage. Eight rats in 14 cubic feet cage have more space for each, than 3 have in 6 cubic feet cage.

One place had a logic that one rat needs 60000 cm3 (cubic centimeters) and second 55000, each additional rat up to 9 rats 50000, when up to 14, then 48000 each when 15 or more, then 46000 each. So ten rats: 60000+55000+

**50000x7**+48000=513000 cm3

Also, if you let your rats run less than a hour a day, it adds 5% and when more than 2,5 hours than 5% less. (no difference when 1-2.5 hours)

So my cage would fit:

It is 60x70x80=336000 cm3

One rat- leftover (33600-60000)=276000

Two rats- leftover (276000-55000)=221000

3=171000

4=121000

5=71000

6=21000

Without runtime, 6.

Runtime, +5%= +16800

21000+16800=37800- no additional rats here.

So the final number for my cage is 6.

...But 115000 cm3 for two rats is more than 4 cubic feet.