Cage Net Space & Group Size Matcher

Advertised cage sizes count walls, shelves and food bowls as "space." Your rats only get what is left: net floor area after fixed furniture, plus climbable volume across levels. Enter the internal dimensions and get a PASS, CROWDED or TOO SMALL verdict with a fix list.

Net Space Calculator

Number of rats

Internal width (cm)

Internal depth (cm)

Internal height (cm)

Levels (incl. ground floor)

Wire / mesh floor (%)

Fixed-item footprint (cm²)

Adult unneutered male in the group?

Measure internal dimensions, not the outside of the frame. Fixed items: estimate length × width of the food bowl, water bottle base, nest box and wheel footprint in cm² and add them.

Verdict

Enter the cage dimensions and click Check My Cage. Results update live as you edit.

Quick Reference: Minimum Floor Area (0.06 m²/rat)

Rats	Min floor area	Example footprint

Floor area is the welfare baseline that no amount of height can replace — rats spend most of their active time on horizontal surfaces.

Volume Benchmarks

2 ft³ per rat ≈ 56.6 L/rat — minimum effective volume including the climbing-value of levels.
Adult unneutered male ≈ 68 L/rat — bucks are larger and less tolerant of crowding (+20%).
Climbing bonus: each extra level adds (floor area × 0.6 m headroom) of usable volume — solid shelves only.
Critter/Nation class: ~91 × 61 × 160 cm — the common sweet spot for groups over 3.