Rate Lens shows how a small difference between a goal's Cost CAGR and an illustrative Portfolio CAGR can become a large future affordability gap over time, at these assumptions. Both curves begin from the same amount so the effect of the two rates stays visible.
Prices show a point. Rates show a path.
A future cost can rise while the resources aimed at it also rise. The balance alone does not tell you whether the future moved closer. The comparison depends on which path compounds faster.
Rate Lens isolates that comparison. The cost curve and resource curve deliberately start from the same illustrative amount. Change the amount, Cost CAGR, Portfolio CAGR, or timeline and the tool redraws both paths at these assumptions.
The annual rate gap is:
Portfolio CAGR − Cost CAGR
A negative result is a headwind: the modeled future cost compounds faster than the modeled resources. A positive result is a tailwind: the resources compound faster. A zero result means the two paths match exactly at these assumptions.
What the defaults mean
The defaults are illustrative and editable. They are not forecasts or source-derived market estimates. The starting amount is used for both curves only to make rate divergence legible.
All figures are nominal. The projected-resource path excludes contributions and withdrawals. The model also excludes taxes, fees, and investment volatility. Portfolio CAGR is a user-entered assumption, not a recommended return, allocation, security, or strategy.
That simplicity is the point of the lens. It shows one mechanism clearly before a fuller plan adds savings flows, multiple goals, taxes, or other real-world details.
The math
Rate Lens uses three equations:
Future cost = today's amount × (1 + Cost CAGR)^yearsProjected resources = today's amount × (1 + Portfolio CAGR)^yearsAnnual rate gap = Portfolio CAGR − Cost CAGR
The straight-line comparison is optional and visual only. It connects the starting amount with the modeled future cost without changing the compound-growth results.
Every output is an educational estimate at these assumptions. The figures are not predictions or financial, investment, tax, legal, or insurance advice.
Use the table beneath the chart to inspect every yearly cost and resource value. Then calculate Aspire Rate for the future you are pricing, or read the full methodology for source windows, formulas, and limitations.