Foot is singular, feet is plural. Why does Google translator fail to distinguish the difference and return "Fuss" for both?
I think what's going on is that when you use Fuß as a unit of measurement then it's used in the singular. So Er ist sechs Fuß groß rather than Er ist sechs Füße groß. If you're using Fuß as a body part then it works as you would expect: Er hat zwei Füße. I don't know if there are other situations where "feet" would translate to Fuß, but this one seems likely, and if so the problem should resolve itself if you switch to the metric system.
BTW, just to head off comments from the spelling police, you're using Swiss spelling. I gather from our previous interactions that you're more familiar with Swiss Standard German than Standard German. Not that Swiss spelling is wrong, but it may raise some eyebrows here since Standard German spelling is more common.