🔗 Open Finance Quest and choose Decision Studio
Learn the trade-off by changing the assumptions
The Finance Quest Decision Studio is an interactive finance lesson about how debt interest, savings growth, and monthly cash flow can affect projected balances. Choose one of three fictional scenarios—credit-card reset, student-loan runway, or cash-buffer building—then change the share of monthly surplus directed to debt and select a 12-, 24-, or 36-month horizon.
The results include projected savings, remaining debt, modeled interest, and net position (savings minus debt). A chart tracks balances through the selected period, and a comparison table shows alternative allocations beside the current plan.
How the simplified model works
At each modeled month, the simulator:
- Adds one month of interest to the current debt balance using the scenario APR divided by 12.
- Adds one month of interest to the savings balance using its scenario rate divided by 12.
- Applies the selected share of the monthly surplus to debt, up to the amount owed.
- Directs the unused surplus—and surplus remaining after debt is paid off—to savings.
For the debt balance, the simplified monthly step is:
monthly debt interest = current debt × debt APR ÷ 12
debt after payment = current debt + interest − payment
This is a deterministic classroom model. It is useful for comparing assumptions consistently, but it is not a complete repayment calculator.
How to explore the scenarios
Credit card reset
This example begins with a $4,800 balance at a modeled 24% APR, $1,000 in savings at 4%, and $400 in monthly surplus. Move the allocation slider toward debt to see how quickly the modeled balance falls; move it toward savings to compare reserve growth while debt remains.
Student loan runway
The student-loan example uses a larger starting balance and a lower modeled rate. Compare its projection with the credit-card scenario to see why starting balance, rate, surplus, and timeframe all affect results.
Build a cash buffer
This scenario has no modeled debt. It illustrates how a monthly contribution and a savings rate combine over time without implying a particular emergency-fund target.
What net position does—and does not—tell you
The tool calculates net position as:
net position = modeled savings − modeled debt
It is a useful way to compare two modeled balance snapshots, but it does not capture every consideration. Liquidity, minimum payments, access to savings, taxes, fees, employer benefits, promotional rates, and the consequences of missed payments can all matter in actual choices. The simulator does not score a choice as universally correct.
Important model limits
The scenarios use fixed rates and a steady monthly surplus. They do not include minimum required payments, fees, taxes, new borrowing, rate changes, missed payments, income changes, emergencies, or account-specific compounding rules. They also do not establish that paying debt or saving is the right priority for a real person.
Use the Decision Studio to build intuition about cash-flow mechanics, not as personalized financial advice. For an actual debt plan, check lender terms and required payments; consider speaking with a qualified financial professional if you need help weighing your circumstances.
For related learning, take the Finance Quest Daily quiz or read the full Finance Quest game guide.
Compare plans in Decision Studio