Keep assumptions consistent
Record whether each amount is expressed in today's dollars or future dollars. A nominal investment return and a real spending target cannot be combined without an inflation adjustment. Use current balances and actual contribution amounts, then create a separate case for planned increases. Employer contributions should reflect written plan rules rather than a generic match percentage.
Use ranges, not a single forecast
Long-term averages do not arrive smoothly and cannot guarantee a future balance. Run lower-return and higher-inflation cases and test retirement age in one-year increments. Obtain a personalized Social Security estimate from the official earnings record instead of entering a guessed percentage of salary. Keep pensions and other income sources separate because their start dates and inflation treatment can differ.
Maintain a reproducible review
Save the assumptions and review date, then update the model annually and after major changes. Change one variable at a time so the effect remains understandable. These tools illustrate mathematical relationships and help identify controllable levers such as contributions, timing, and spending. They do not select investments, account for every tax rule, model market sequence precisely, or replace individualized retirement advice.
Separate evidence from preferences
Account balances, contribution records, plan rules, and official benefit estimates are evidence. Retirement age, spending goals, return assumptions, and desired safety margins are planning choices. Labeling them separately prevents an optimistic preference from being mistaken for a verified fact. When a result changes, identify whether new evidence arrived or a preference changed. That distinction makes annual reviews more useful and gives a qualified adviser a clearer record when taxes, pensions, healthcare, or withdrawal sequencing require individualized analysis.
Primary sources used for this collection
Source links and page scope were checked during the August 2026 review. Verify current rules and written terms before making a financial decision.