Client Education
How Federal Income Taxes Work
Federal tax rates have changed dramatically over time. The more important planning lesson is that a higher bracket does not tax every dollar at that higher rate: income fills brackets one layer at a time.
Live plan: This lesson uses the conversion tax estimator inputs from the main calculator.
1913-2026
Marginal Rate
Federal Bracket
Added Conversion Income
Historical Perspective
Top Federal Marginal Tax Rate By Year
This chart shows the highest statutory federal individual income-tax rate, not the rate paid by a typical household.
Top marginal rate Current top rate
Your Conversion
What the added income costs
The applied estimator scenario is summarized here.
Income before conversion$0
Annual Roth conversion$0
Added federal income tax$0
Conversion after federal tax$0
Progressive Tax Lesson
Income fills each bracket in layers
Only the dollars inside a bracket are taxed at that bracket's rate. A conversion can span several brackets, which is why its blended rate may be lower than its highest marginal rate.
$0 taxable income$0 taxable income
Calculation Detail
Where the planned income lands
The added-income column isolates the portion of each bracket filled by the annual Roth conversion.
| Federal rate | Modeled bracket range | Baseline taxable income | Added conversion income | Total after conversion |
|---|
Sources And Scope
Historical rates for 1913-2017 are based on IRS Statistics of Income Historical Table 23; later years use published IRS federal tax schedules. Historical top marginal rates are educational context only: taxable-income definitions, deductions, exemptions, filing rules, and surtaxes changed over time, so this module does not recreate a historical tax return. Current plan calculations use the calculator's embedded 2026 federal brackets and the selected tax-estimator assumptions. Sources: IRS Historical Table 23, IRS 2026 inflation adjustments, and IRS federal rates and brackets.