Google has a traffic estimator (aka Traffic Estimator Sandbox) that allows you to check the amount of clicks each key term/phrase will generate per day, but they require you to put in a lot of information (regarding CPC, target country, etc.).
So, if you bookmark this page, this form could just make things a little bit simpler:
[keyword] – if you want to measure an exact search term/phrase.
“keyword” – includes phrase with possible search terms added to it.
keyword – broad/general search.
-keyword – negates a term.
PS: I don’t think anyone else has posted this form on any websites, but it’s always possible.