You have to include taxes as part of your expenses. I cannot figure out how to link to other threads on here using the iPad App, but I recently started a thread about what tax rate people use in their calculations. The best suggestion was to use an online tax estimator like TurboTax to see. It turns out that it really is an amazing range of rates depending on how much of your money you are taking from where. My effective tax rate is likely to be about 12% or less in retirement (Federal AND State). With each state being different of course.you have to know how your state treats the different income sources.
30% tax rate is possible but would mean you are taking a HUGE amount of money out of your tax deferred accounts. Remember money you take out of your currently taxed savings is only potentially subject to being taxed (Federally) on the part of the withdrawal which is dividend or capital gains (return of principle does not get taxed or even counted to determine you tax bracket) and currently only subject if you end up above the 15% marginal tax bracket which is something like $70,000 right now.
Example-(ignoring Social Security and pensions as sources of income and ignoring exemptions and carry over capital losses from prior tax years which allow you to deduct from these crude numbers):
You need $100,000 a year. You made $30,000 in dividends from a taxable account. From your taxable account you sell some stock to generate $35,000 but the capital gain is $10,000 of it, the rest return of your principle. You take $41,176 from your IRA or 401k. Total to spend = $100,000. Federal taxes owed = 15% of that last $41.176 only. Federal tax rate on the total is 6.18%. Take all $100,000 of it from your IRA or 401k and you would owe 15% Federally, so you would have to take out $117,647 to be left with $100,000 to spend. (assuming you owe ZERO State taxes-which is not likely in most states)