Purpose
The calculator answers a bounded planning question: under a stated set of ages, income, saving, spending, return, inflation, housing, and retirement-income assumptions, how might household savings change year by year? It is designed for comparison and education, not prediction or individualized advice.
Annual calculation sequence
- Start from the current retirement-savings balance and the selected age timeline.
- While working, apply modeled employee savings and employer match within the visible limits.
- Apply the selected annual investment-return assumption to modeled savings.
- Increase modeled wages and expenses using the selected inflation assumption where applicable.
- After retirement, compare spending with Social Security and supported fixed-income streams.
- Withdraw any modeled shortfall from savings and record the year-end result.
- Repeat through the selected plan-end age and return the complete annual series.
Two-person planning
Two-person mode keeps separate current ages, retirement ages, life-expectancy ages, wages, Social Security estimates, workplace contributions, and fixed-income timelines. These feed one household savings balance and one shared spending assumption. The calculation timeline continues until the later plan-end age.
Structured income and spending
Saved scenarios may include pensions, annuities, part-time income, itemized expenses, and limited-duration future income or expenses. Itemized expenses do not silently replace annual spending; you must explicitly copy the displayed total. User labels and row identifiers are excluded from calculation-engine snapshots.
Housing
The model can include a current home value, mortgage balance, housing payment, property tax, mortgage term and rate, and home appreciation assumption. Housing output is an estimate based on those inputs and is not an appraisal or mortgage statement.
2026 IRA owner RMD estimate
The public RMD tool accepts an IRA type, the account owner's birth year, and the December 31, 2025 account balance. The calculation runs only in the browser with Decimal arithmetic. The birth year, balance, special-case selections, and result are not uploaded, saved, placed in the URL, or written to analytics.
For a supported owner who is due for a 2026 RMD, the estimate divides the prior year-end balance by the Uniform Lifetime Table factor for the owner's age on December 31, 2026. The embedded table covers ages 73 through 119 and uses the published 2.0 factor at age 120 or older. The result is rounded to cents with Decimal half-up rounding.
For 2026, an owner born in 1953 is identified as having a first RMD year and is shown the general April 1, 2027 first-year deadline warning. Owners born in 1954 or later receive a not-due result for 2026. The tool routes inherited IRAs and an account whose sole-beneficiary spouse is more than 10 years younger away from the Uniform Lifetime estimate rather than substituting an unsupported factor.
The tool does not cover inherited-account schedules, the Joint and Last Survivor Table, employer-plan still-working exceptions, account aggregation or prior shortfalls, excise tax, qualified charitable distributions, withholding, or income tax. Current IRS required-minimum-distribution guidance and Publication 590-B must be reviewed before the tool is presented for another distribution year.
Social Security taxability screening
The public taxability tool adds one-half of entered net Social Security benefits, other income entered for the quick check, and tax-exempt interest. Decimal arithmetic is used in the browser, and the entered values are neither uploaded nor saved.
For a 2025 federal return, the tool compares that sum with $25,000 and $34,000 for single, head-of-household, qualifying-surviving-spouse, and qualifying married-filing- separately situations, or $32,000 and $44,000 for married filing jointly. A married- filing-separately taxpayer who lived with a spouse during the year is directed to the special IRS worksheet rather than a normal threshold result.
The output is only a band: at or below the base amount, between thresholds, above the higher threshold, or special worksheet required. It does not calculate the exact taxable portion, taxable income, tax bracket, credits, withholding, state tax, Medicare premiums, or tax owed. Thresholds and instructions must be reviewed against the current IRS Publication 915 before the tool is rolled into a new filing year.
Known limitations
- No randomized market paths or sequence-of-returns probability.
- No account-by-account federal or state tax calculation.
- No inherited-account, employer-plan, or special-table RMD calculation.
- No Medicare premium, IRMAA, long-term-care, or insurance pricing model.
- No automatic Social Security benefit estimate or claiming optimization.
- No securities recommendation, asset allocation, or investment suitability analysis.
- No guarantee that future returns, inflation, laws, or benefits match an assumption.
Versions and reproducibility
Calculation responses include a methodology version and engine version. Saved results also retain normalized inputs, an input hash, timestamps, status, and the output snapshot needed to explain which engine produced a historical comparison. Methodology changes require tests against verified legacy cases and a new version when results can change.
Using the result responsibly
Change one assumption at a time, compare multiple scenarios, and treat missing data as unknown rather than zero. Verify Social Security, tax, Medicare, retirement-plan, and other rule-based inputs against current official sources. Use qualified professionals for decisions requiring individualized investment, tax, legal, or benefits advice.