What pecent of people in the US?

Would you guess play chess? What percent are rated?

Just completely guessing here, I have no idea but...

Less than 1% rated by the USCF -- a bit less than half know the rules of movement.

 You mean a bit less than half of the unrated players?

Yeah.

There's something like 300 million people in the US.  So I'm guessing less than 3 million are active USCF members (not a tough guess :).  I think a little less than 150 million know how the pieces move (total guess work here).

You mean 1.5 million. Why would they be in the USCF if they didn't know how the pieces move?

Up here, due to a decades-old policy of trying to make high-school students pay lots of money to play chess, the CFC has perhaps 2K active members in a national population of 33M. That's 2 in 33000, which might explain why the word "chess" doesn't appear in many government budgets.

Of the total population of the United States, ~300 million, I'm saying less than half (which is 150 million) know how the pieces move.

When you asked "unrated players?" I thought you were saying unrated as in all those millions of people outside of the USCF that have never played a tournament game.  I was never breaking down the 1% further i.e. into 1.5 million.

In all of Canada there are only 2,000 active members?  I suppose a lot of your chess players get together in clubs or play online?  Surely there are more than a few thousand players in Canada :)

 Greed setting in, as usual. What's the weather like in your part of Canada? I think I would like it much better than where I live.

Unfortunately, chess is not part of mainstream US culture.  The offical USCF website lists its membership as "over 80,000 members", which I take to mean less that 81,000.  Even if we round it up to 81k, if we asume the US has 300 million people that .00027 percent who are active USCF members.  There are more people than that who play regularly, but they play here, or on yahoo, or ICC, or at the local club without ever getting an "official" rating.  I imagine lots of people have learned the rules at some point, but I doubt that more than a few hundred thousand to a half million who play the game on a regular basis.

 About one in four thousand. No wonder I've never met anybody who plays, that I know of.

Move to a big city in TX or CA and 1 in 4000 means the chess club will have at least a few hundred members

When I joined as a teenager in the late 70's, the CFC had about 3K members. I was in the country's top 300 rated players for a little while, which is about as noteworthy as being the 5th-best inland fisherman in Libya :). The CFC was proud of a survey where chess (somehow) came out as the game played by more people in Canada than any other (euchre? checkers?), but they couldn't get (new) people to fork over an annual membership fee (which bought you very little) plus tournament fees (which for newbies bought you very little). I don't come across casual chess players often; it's nearly always at clubs.

And since you asked, the weather is a bit too cold to be playing chess in the park -- hovering around freezing.