Take a look at the Tax Foundation’s recently updated interactive tax calculator. By plugging in some basic information (filing status, number of dependents, and income), it will estimate your federal tax rate under three scenarios: (1) the full expiration of the Bush and Obama tax cuts, (2) the Republican plan to extend the Bush tax cuts, and (3) President Obama’s plan to partially extend them.
If you need a refresher on the Bush tax cuts and why they are expiring, The Tax Foundation breaks it down here.