Rat cage size calculator

Rats need at least 60 liters of cage volume per rat, a floor of at least 2400 cm² (e.g. 60×40 cm) and a height of at least 50 cm. Enter your cage's inside measurements to see how many rats it fits.

The same calculator is in the free Rattitude Care app. Get the app

Bar spacing

Even with enough volume, rats can escape or get their heads caught if the bars are too far apart. The RSPCA says the spacing should be small enough that your rats can't poke their heads through.

• Babies and young rats: maximum 1 cm — young rats squeeze through wider gaps.
• Adult rats: maximum 1.3 cm (½ inch). Even adults can get their heads stuck in 1.9 cm (¾ inch) gaps.

How the calculator works

It multiplies the three measurements to get the cage's volume in liters (length × width × height in cm ÷ 1000), then allows 60 liters — about 2 cubic feet — per rat. The result only counts if the floor is at least 2400 cm², so rats can walk and stretch out, and the cage is at least 50 cm tall, so they can climb and you can hang hammocks. Measure the mesh part of the cage only: a deep plastic base tray adds height on paper but not climbing space.

These are the same minimums the Rattitude Care app uses, and they are minimums. The RSPCA advises making a rat cage as large as possible, with platforms, ramps and hammocks at different heights, a solid floor rather than wire mesh (wire floors can lead to foot problems), and one more shelter than you have rats. Rats are social and need the company of other rats, so plan for at least two.

Common questions

How big should a cage be for two rats?

At least 120 liters (about 4.2 cubic feet) of usable volume, with a floor of at least 2400 cm² (for example 60 × 40 cm) and a height of at least 50 cm. A 60 × 40 × 50 cm cage is exactly 120 liters. More space is always better.

How many rats can live in my cage?

Multiply length × width × height in centimeters and divide by 1000 to get liters, then allow at least 60 liters per rat. For example, an 80 × 50 × 70 cm cage holds 280 liters — enough for up to 4 rats, as long as the floor and height minimums are met.