Answer: 3.46 acres!
A 15 cat study in Alice Springs, Australia, conducted by Alice Springs Town Council, found that the “core home range area of the domestic cat was 1.4 hectors on average”. This is 3.46 acres. That is how much space an average house cat needs if we make the presumption that Australian domestic cats are similar to all other domestic cats in terms of how far they wish to travel and how much space they need. I suspect that they are although Australia has wide open spaces which may encourage freeroaming cats to use those spaces.
I’m being a bit provocative but on this basis full-time indoor living does not provide enough space for the domestic cat but they adapt admirably. Cats can settle into a home range which is much smaller than one without limits. The interesting point though is that when there are no limits it appears that about 3 1/2 acres is the chosen space that a house cat needs.
However, the study is based on a small sample of domestic cats. The cats were tracked with a special device. They were all freeroaming cats. But, as mentioned, they were entirely domestic. The cats were recorded outside the boundaries of the property on 47% of occasions, otherwise the cats stayed within the owner’s property.
The cats travelled 31 m from home on average. The farthest distance from home averaged 352 m. On average the cats did not venture further from home at night compared to daytime. This confirms that domestic cats are not crepuscular like many wild cat species. They can be active across the 24 hours of the day. My cat likes nighttime, however.
I have always felt that domestic cats like a whole range upwards of about 5 acres. When cats go missing they are often found not that far from their owners property; certainly within a few acres. Obviously it depends upon the individual cat and females in general across the wild cat species have considerably smaller home ranges than males. The same would apply to domestic cats. Does this mean that female domestic cats are better adapted to the full-time indoor lifestyle?