Turbo Tax has a tool called the IRA Calculator that will walk you through the calculation. Unfortunatly, it is currently being updated, https://turbotax.intuit.com/tax-tools/calculators/ira/
However, in the meantime, here is another tool I've found helpful, https://www.fidelity.com/calculators-tools/ira-contribution-calculator
Another way where your income will already be calculated through TurboTax is to pretend to put in different amounts in the Retirement Savings Credit and the system will do the calculations for you. You can change your contribution amount to see what works for you.
1. Go To Federal, then Deductions and Credits.
2. Select Retirement and Investments, choose Retirement Savings Credit
This is walk you through the program. You will be able to see what will be your maximum benefit.
