Take home salary calculator from the Annual Gross package

Since most of us, like I, are in the hunt for a good employer and getting the precious H1B, most of the time I see questions like will XX K USD enough for this state etc.

I have a similar question. Can anyone suggest a good website which helps you calculate the Take Home monthly salary after state/ federal/ medicare taxes etc.

I went through some websites online but there were so many fields on the page and I didn’t have any clue of what impact those fields have.

Mostly candidates are only given an Annual Gross package and may be at times the individual or dependent medical insurance premium deduction.

Is that enough to at least come close to the real take home amount?

Please let me know if you have any idea on these calculators

ADP has a good calculator to know take home salary - http://www.adp.com/tools-and-resources/calculators-and-tools/payroll-calculators/salary-paycheck-calculator.aspx

Each field has help text as well, in case you want to know what they stand for.