Reference Tables: RMDs, Tax, and Mortgages

Three forces take money on schedules nobody negotiates: the IRS requires withdrawals, the tax code takes its share of earnings, and the mortgage takes interest before principal. Each is computable in advance. Price all three before trusting a plan.

Required minimum distributions

Tax-deferred accounts carry a condition. From the RMD age, the IRS requires a yearly withdrawal whether the cash is needed or not. The amount is the prior year-end balance divided by a divisor from the Uniform Lifetime Table. The divisor shrinks every year — 26.5 at 73, 20.2 at 80, 12.2 at 90 — so the required percentage rises with age while the balance falls.

The start age depends on birth year. Births from 1951 through 1959 start at 73. Births from 1960 on start at 75. Withdrawals before the start age are voluntary. Missing a required withdrawal brings a penalty on the amount not taken, reducible when corrected promptly.

Two properties matter for planning. First, RMDs are transfers, not income: money forced out above spending need is reinvested after tax, which is how the spend-down step treats them. Second, the divisor applies to the whole tax-deferred balance, so the schedule grows with the balance. Enter a balance and birth year in the RMD estimator for the full schedule.

Working-years tax

Derived savings subtract tax from inflows before a dollar is counted as saved. The estimate follows the 2025 single-filer schedule on taxable inflows minus the $15,000 standard deduction, plus 7.65% payroll tax on wages to the wage base. It is rough by design: no state tax, no joint filing, no credits.

Roughness is acceptable here because the purpose is sizing savings, not filing a return. A few thousand dollars of tax error moves the savings figure slightly. Pretending tax does not exist moves it enormously. The tax estimator shows the bracket-by-bracket breakdown behind any salary.

The mortgage

A fixed payment covers that year's interest first, and only the remainder reduces principal. Early years are therefore mostly interest. On a $300,000 balance at 6.5% with $24,000 yearly payments, the first year sends roughly $19,500 to interest and $4,500 to principal. The proportions invert over time without any action by the borrower.

For retirement timing, the payoff year matters more than the rate. Expenses step down by the full payment when the loan amortizes to zero — the payoff cliff visible on the lifetime expenses timeline. Raising the payment moves the cliff closer at the price of current cash flow. The mortgage payoff calculator prices any payment: payoff year, total interest, and the full schedule. A payment below yearly interest never pays off the loan, and the calculator says so plainly.

Using the three together

Run all three before finalizing inputs elsewhere. The RMD schedule belongs on the lifetime income timeline. The tax figure disciplines the savings derivation. The payoff year anchors the expense timeline. Each calculator links back here, and each table states its sources.