Rat Cage Calculator

What this does

So you want to know if your cage is big enough, and for how many rats. This works it out. Enter the cage dimensions and the space you want to allow per rat, and it gives you the total cage volume and roughly how many rats that fits. It is a quick way to sanity check a cage before you buy it or add to your group.

How to use it

1. Enter the cage height, length, and width, each with its unit.
2. Enter the space per rat, and pick the unit.
3. Tap Calculate to see the total volume and the number of rats it suits.

Not sure what to put for space per rat? The next section gives you a sensible figure.

How it works

It is simple volume maths. First it works out the cage volume from the three dimensions:

cage volume = height × length × width

Then it divides that by the space you allow per rat to get a capacity:

number of rats = cage volume ÷ space per rat

So a 10 cubic foot cage, at 2.5 cubic feet per rat, comes out at four rats. Everything is converted to consistent units first, and it all runs on your device.

How much space per rat

Since you choose the space per rat, here is a sensible figure to use. A commonly cited minimum is around 2 to 2.5 cubic feet per rat, so putting that in the box gives you a reasonable baseline. The important word there is minimum. Rats are active, curious animals that spend most of their lives in the cage, so go bigger than the minimum whenever you can, and treat the result as a floor to clear, not a target to hit.

Beyond the numbers

Raw volume does not tell the whole story, so a couple of things to keep in mind. Rats need horizontal floor space to run and solid levels to climb, which means a tall, narrow cage that scores a big volume is not as good as a roomier, multi level one with the same number. Solid floors beat bare wire, which can cause sore feet, and the bars need to be close enough together that a rat cannot squeeze out. And the big one, rats are deeply social and should never live alone, so plan for at least a pair, which means at least doubling the space a single rat would need. A bit of extra room is never wasted on a rat.

Questions people ask

References

1. The Vet Desk. How to Choose the Right Cage Size for Pet Rats. https://thevetdesk.com/pet-health-wellness/rats/pet-rat-cage-size/