<prompt>  Human: If I increase my contribution, that means Id have less federal and state taxable income. But Im having difficulty trying to figure out what my final paycheck would look like mostly because I dont know if the percentage taken out of my taxable income would change if I increase my contribution.Is there a calculator where I can input various pre-tax deductions and it will figure out what federal and statecity taxes will be taken out? I dont know if such a thing exists since it would have to know each state and citys taxes, but who knows. 