In Georgia what is tax amount taken out of monthly salary of 1800?

You can use the following calculator to determine how much tax will be deducted from your paycheck:

http://www.paycheckcity.com/NetPayCalc/netpaycalculator.asp

Remember that the amount of income tax deducted depends on how you fill out Form W-4 that you give to your employer. It is not the real amount of tax you owe. The real amount is calculated when you fill out your tax return at the end of the year. When you fill out and file your tax return, you will get a refund if too much was deducted or you will pay more if not enough was deducted.