CCH has released its 2013 Fiscal Cliff Estimator, where you can see what the Federal income taxes will be under three of the options being discussed. I can’t vouch for the precise accuracy of all the calculations. However, based on all of the footnotes, it does appear that they have put some time and effort into these calculators.
I’m not sure that I would use this for actual tax planing purposes, but it does help give a flavor for how much money is at stake as our rulers in DC enjoy their taxpayer funded vacations.
For example, I entered MFJ with $150,000 of Taxable Income, $10,000 of LTCG and $500 of Dividends and it gave the following results for total Federal income tax.
Current 2012 Tax Rates: $31,354.00
Full Extension of Bush-Era Tax Cuts (Republican Plan): $31,040.50
Presidential and Senate Democratic Proposal: $29,465.50
Expiration of the Bush-Era Tax Cuts (If Congress Does Not Act): $36,391.50
Tax Guru - Ker$tetter Letter 