Retirement Tax Bracket Blend Calculator
Blend taxable, Roth and Social Security income into one effective tax rate to see how tax diversification lowers your retirement tax bill.
How it works
Taxable income = traditional + taxable Social Security · Tax = taxable × marginal rate · Blended rate = tax ÷ total income × 100
In retirement your income can come from three tax buckets: pre-tax accounts taxed as ordinary income, Roth accounts that are tax-free, and Social Security that is only partly taxable. Mixing withdrawals across these buckets — "tax diversification" — lets you pull tax-free Roth dollars to hold your taxable income and marginal rate down. The blended rate here shows the tax you actually pay as a share of everything you receive, which is typically far below your marginal bracket.
Worked example
Drawing $40,000 from a traditional account, $15,000 from Roth and $10,000 of taxable Social Security gives $65,000 gross but only $50,000 taxable. At a 12% marginal rate the tax is $6,000 — a blended rate of 6,000 ÷ 65,000 = 9.2%.
Frequently asked questions
Why is my blended rate lower than my tax bracket?
Your marginal bracket only applies to taxable dollars. Because Roth withdrawals are tax-free and part of Social Security escapes tax, the tax you pay measured against your total income is lower than the bracket suggests.
How much of Social Security is taxable?
Depending on your combined income, anywhere from 0% to 85% of your benefits can be taxable at the federal level. Enter the dollar amount you expect to be taxable rather than your full benefit.
What is tax diversification?
It is holding money across pre-tax, Roth and taxable accounts so that in retirement you can choose which bucket to draw from each year, controlling your taxable income and smoothing your tax rate across time.
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Educational estimate using simplified assumptions — not tax, legal or financial advice. Verify limits and rules with the IRS or a qualified advisor.