Rat Cage Size Calculator

Use our rat cage size calculator to find cage volume (cu ft) from height, length, and width, and estimate the maximum number of rats the cage can house using a 3 cubic feet per rat guideline. Includes tips on minimum cage size for 2 rats and what to consider beyond volume.

Height (ft)
Enter cage height in feet (ft).
Length (ft)
Enter cage length in feet (ft).
Width (ft)
Enter cage width in feet (ft).
Results
Maximum number of rats this cage can house
Estimated using a baseline of ~2.5 cubic feet per rat.
Cage volume (cu ft)
Volume = height × length × width.
Volume is a rough proxy for space. Floor space, levels, and enrichment matter too.
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How Big Should a Rat Cage Be?

A good rat cage should provide enough space for climbing, exploring, and resting areas. Rats are active, social animals that do best with room to move and plenty of enrichment.

A common starting guideline is about 3 cubic feet of cage volume per rat. This calculator uses that guideline to estimate how many rats a cage can house based on its interior dimensions.

Volume is not the only factor. Bar spacing, airflow, layout, and usable floor levels matter too. Treat the number as a practical estimate, then choose a cage that supports safe climbing and enrichment.

Rat Cage Size Formula

This calculator computes cage volume, then estimates the maximum number of rats using a 3 cu ft per rat guideline.

Cage volume =
Volume(cu ft) = Height(ft) × Length(ft) × Width(ft)

Use interior dimensions if possible for the most accurate volume.

Maximum number of rats =
MaxRats = floor(Volume(cu ft) ÷ 3)

Uses 3 cubic feet per rat. The result is rounded down to a whole number of rats.

Height
= Interior cage height (ft)
Length
= Interior cage length (ft)
Width
= Interior cage width (ft)
Volume
= Cage volume (cubic feet)

How to Use the Rat Cage Calculator

  1. 1

    Enter the cage height (ft).

  2. 2

    Enter the cage length (ft).

  3. 3

    Enter the cage width (ft).

  4. 4

    The calculator returns cage volume (cu ft) and the estimated maximum number of rats the cage can house.

Frequently Asked Questions

How big should a rat cage be?

A common guideline is around 3 cubic feet per rat, plus enough levels, hides, and enrichment for climbing and exploring. Bigger is usually better, especially for active groups.

What is the minimum cage size for 2 rats?

Using the 3 cu ft per rat guideline, 2 rats would need at least about 6 cubic feet of volume. More space is recommended if you can provide it.

Does cage volume alone determine how many rats I can keep?

No. Volume is a useful starting point, but layout (levels), ventilation, bar spacing, and enrichment all matter. A tall cage with no usable shelves can feel smaller than a well-designed multi-level setup.

Should I round up the number of rats?

No. If you are using a minimum-space guideline, it’s safer to round down. More space generally improves comfort and reduces stress.