What the two columns measure
Both scenarios receive the same nominal deposit at the beginning of each projection year and then earn the same assumed annual return. The Traditional balance is reduced by the assumed withdrawal tax rate at the endpoint; the Roth balance is treated as qualified and tax free. Returns are constant hypothetical inputs, not forecasts.
Why equal contributions do not establish a winner
A deductible Traditional deposit can reduce current tax, while the same Roth deposit is made without that deduction. The calculator reports total assumed deduction savings separately but does not invest them. With equal opening balances and deposits, the account balances before withdrawal tax are equal; a positive withdrawal tax makes the Traditional after-tax account balance lower. That arithmetic does not prove Roth is better.
How to use the model
Enter whole current and projection ages, an annual deposit, starting balances and assumed return/tax rates. Projection age must be at least 60, and qualified Roth status is still an explicit assumption. Check the contribution applied in each schedule row. Changing inputs recalculates displayed results; Clear hides the result. Invalid ages, negative balances and out-of-range rates produce an input message.
2026 limits are a reference cap, not an eligibility decision
The IRS specifies a $7,500 combined IRA limit for 2026, plus $1,100 catch-up for eligible people age 50 or older. Taxable compensation can impose a lower limit. This model applies the 2026 amounts throughout the projection and does not forecast future inflation adjustments. Its age-based catch-up convention is illustrative; verify eligibility for the actual tax year.
Deductibility and direct Roth contributions need separate checks
Traditional contributions are not always deductible. Income, filing status and whether you or a spouse has a workplace retirement plan can matter. Direct Roth eligibility also depends on modified adjusted gross income and filing status. This page does not calculate phase-outs, nondeductible basis, conversion taxes or pro-rata treatment.
Withdrawals are simplified
The Traditional scenario assumes the whole balance is taxable. Roth qualified-distribution rules include a five-year condition and an age or other qualifying event. Early distributions, conversions and inherited accounts have additional rules. RMD withdrawals, state taxes, inflation, changing returns and tax brackets are excluded.
Make a like-for-like planning comparison
For a fair spending-budget comparison, account for the Traditional deduction and what happens to that money. You may need a separate taxable-investment model with its own fees and tax drag. Test sensitivity to returns and tax rates rather than treating one assumed path as a forecast. Consult a qualified tax adviser about your actual eligibility and withdrawals.