How It Works

A scenario planner, not a forecast

The planner compares the savings path you describe today with a hypothetical retirement goal you set yourself. It runs the arithmetic in your browser and returns one plain number: the estimated gap or surplus at your chosen retirement age.

Nothing here predicts markets. Every figure is a hypothetical projection built from the values you enter, such as contribution rate, expected return, target annual income, and retirement age. Change an input and the comparison changes with it. That is the whole point: the tool exists for exploring scenarios, not for delivering a verdict.

What the comparison can and cannot tell you

  • It can show how sensitive your outcome is to a single change, such as adding one more contribution each month.
  • It can place your current path beside alternative paths so the differences appear in the same units.
  • It cannot model taxes, healthcare costs, or sequence-of-returns risk with precision.
  • It cannot replace a conversation with a qualified professional about your full situation.

A gap is a signal to consider further planning, not a crisis. A surplus is a hypothetical result, not a guarantee of future results.

Methodology

Six steps from your inputs to a projected gap

  1. Start with two numbers

    You enter your current retirement savings and the annual income you would like in retirement. No account, no upload, nothing else required.

  2. Apply the stated assumptions

    The planner uses fixed, published assumptions for investment return, inflation, retirement age, and how long the money needs to last.

  3. Project the balance year by year

    Contributions, growth, and inflation are applied one year at a time until retirement age, then the balance is drawn down against your target income.

  4. Compare the projection with your goal

    Projected savings and the lifetime cost of your target income are placed side by side so a shortfall or a surplus becomes visible.

  5. Read the result as a range

    Because returns and inflation vary, the output is presented as a range rather than a single figure. A gap is a signal to consider further planning, not a crisis.

  6. Test one change at a time

    Adjust the contribution or the retirement age and watch the range move. Each run is independent, so you can compare scenarios on the scenario table.

Assumptions

What the model takes as given

Each projection compares two figures: what you have saved today, and what a hypothetical goal at your target retirement age would require. The tables below list every value the planner uses, the default it starts from, and whether you can change it. Defaults are starting points, not recommendations.

Inputs you can change

Editable planning inputs, default values, and notes
InputDefaultEditableNote
Current retirement savings$150,000YesCombined balance of employer plans, IRAs, and retirement-earmarked taxable accounts.
Current age45YesSets the length of the accumulation window with your target retirement age.
Target retirement age65YesThe year contributions stop and withdrawals are assumed to begin.
Target annual retirement income$60,000YesEntered in today's dollars, then inflated to the target year.
Monthly contribution$800YesAssumed to continue unchanged until the target retirement age.
Estimated Social Security benefit$1,900/moYesA user-supplied estimate. Not provided, verified, or endorsed by any agency.

Assumptions held constant

Fixed model assumptions applied to every scenario
AssumptionValueEditableNote
Inflation2.5%NoApplied to both the income goal and the future value of contributions.
Pre-retirement return6.0%NoHypothetical annual growth while contributions continue.
Post-retirement return4.0%NoHypothetical annual growth after withdrawals begin.
Withdrawal horizon25 yearsNoWithdrawals are modeled through age 90.
Tax treatmentPre-taxNoIncome taxes on withdrawals are not modeled in this version.
See how each figure feeds the projection Compare the default scenarios Frequently asked questions

Disclaimer

What this planner is, and what it is not

This tool is for educational purposes only and does not constitute financial, investment, or tax advice.

The scenario comparisons on this site are illustrations built from the assumptions you enter. They help you see how a savings path behaves under different inputs. They do not recommend any specific product, account, or strategy.

  • 01All projections are hypothetical and not guarantees of future results.
  • 02This tool is not affiliated with the Social Security Administration, the IRS, or any government agency. Any benefit figure shown is a simplified modeling input, not an official statement.
  • 03We do not store or transmit your inputs. All calculations happen in your browser, and nothing you type is sent to our servers.
  • 04Returns, inflation, tax rules, and health costs change over time, so real outcomes will differ from any single modeled path.

A gap is a signal to consider further planning, not a crisis. If a scenario leaves you with open questions, a licensed financial professional or tax advisor can review your situation in detail.