Can I do calculation of income tax myself? What r the rules one must apply?

it’s called turbo tax and your’e not supposed to use text syntax on fluther. Welcome!

Yes you can. If you have a simple return you can use the information in the instruction booklet. Or go to IRS.gov and use their free calculators for the EZ-1040 form.

yes you can but it can get quite complicated if you have many source of income and are eligible for deductions etc. see tax calculator at http://www.makemyreturns.com/income-tax-calculator/income-tax-calculator.aspx to quickly get tax estimate

That’s a clever spam method but it’s still spam.

Pick up a Form 1040 and follow the instructions.