One man's freedom ends where an other man's begins.
That is to say, everyone should be free to do as he wishes, as long as he doesn't hurt anyone else in the process, either physically, mentally, emotionally or any other way. Including ruining the planet for those that come after us :-) Some people may argue that this should be extended to every living thing (veggie, vegan) but that's a different discussion.
So the way to measure your freedom is to look at the things you're not allowed to do, and compare them to this basic tenet. The more things you can't do, the less freedom you have.
Americans seem to have a lot less freedom that they think, indeed, but they're still doing pretty good compared to a lot of other countries.