If my net salary will be $850.00 a week, how much will be my gross
salary? and i will be pay with de form W 2

I have gathered some info that will help to give you a net-to-gross
approximation. Keep in mind that most U.S. states have their own
income taxes, and a few cities do, too, and the rates vary.

Using the "Net to Gross Paycheck Calculator," and assuming a weekly
pay period, a filing status of "single", and no state or local income
taxes, a net paycheck of $850 would be generated by a gross paycheck
of $1,124.62. This uses the withholding schedules for 2006.

Net paycheck $850.00
FICA OASDI    $69.73
FICA Medicare $16.31
Federal tax  $188.58

Here is a screen capture of the results:

http://www.mortalwombat.com/Special/paycheck.gif

Net to Gross Paycheck Calculator
http://www.dinkytown.net/java/PayrollGross.html

You can find links to information about your state's income tax (if
any) on this page (scroll down the page about halfway to see the list
of states):

Salary Wizard: California & other state tax rates information
http://swz.salary.com/salarywizard/layouthtmls/swzl_statetaxrate_CA.html

This page has a Gross Pay Calculator which includes state income tax.
Just enter the data and select your state, and the calculator will do
the rest:
 
Paycheck City: Gross Up Calculator
http://www.paycheckcity.com/coAmCheck/grossupcalculator.asp

My Google search strategy:

Google Web Search: "net to gross" paycheck
://www.google.com/search?hl=en&q=%22net+to+gross%22+paycheck

Google Web Search: "gross-up" calculator tax
://www.google.com/search?hl=en&q=%22gross-up%22+calculator+tax

Google Web Search: "state income tax" calculator
://www.google.com/search?hl=en&q=%22state+income+tax%22+calculator

I hope this is helpful!

Best regards,
pinkfreud

I doubt that anyone can answer this in a very precise way without
knowing where you live (so that city and state taxes can be
calculated) and what income tax deductions you are taking.

Does this help?

http://www.dinkytown.net/java/PayrollGross.html

USA TAx rates can be found at www.scopulus.co.uk/taxsheets/