Result: Result: Invest, Advantage: PLN 3,003, Break-even: 6.5%
Financial decisions
Repay debt or invest?
This calculator simulates both scenarios month by month to show which approach grows your net worth faster. Get a clear recommendation and the break-even return where investing beats overpayments.
Financial advantage
PLN 3,003
Investing PLN 1,500 monthly can build a portfolio about PLN 3,003 higher over 10 years.
Range: 10,000 PLN – 5,000,000 PLN
Repay vs invest
Debt repayment strategy
Net worth
PLN 256,624
Assets after payoff: PLN 256,624
Debt fully repaid
Investing strategy
Net worth
PLN 259,627
Assets: PLN 259,627
Debt remaining: PLN 0
Break-even return
6.5%
Above this return, investing starts to look stronger.
Instalment for PLN 120,000
PLN 1,363
Minimum instalment required to repay within the horizon.
Net worth over time
Net worth (assets minus debt) at the end of each year.
- Overpayment strategy
- Investing strategy
Show data as a table
| Year | Overpayment strategy | Investing strategy |
|---|---|---|
| 1 | -PLN 92,644 | -PLN 92,601 |
| 2 | -PLN 63,455 | -PLN 63,268 |
| 3 | -PLN 32,312 | -PLN 31,864 |
| 4 | PLN 917 | PLN 1,756 |
| 5 | PLN 36,458 | PLN 37,750 |
| 6 | PLN 74,568 | PLN 76,285 |
| 7 | PLN 115,434 | PLN 117,541 |
| 8 | PLN 159,253 | PLN 161,710 |
| 9 | PLN 206,240 | PLN 208,999 |
| 10 | PLN 256,624 | PLN 259,627 |
The lines show net worth (assets minus remaining debt) at the end of each year.
A sharp rise of the overpayment line means the debt is gone and the whole instalment moves into investing.
Good to know
Build your scenario
Enter debt details, expected return and investing horizon. The algorithm compares two strategies: aggressive overpayment versus investing the surplus while paying the minimum instalment. The result is a recommendation plus the net-worth gap.
- The overpayment path assumes every repaid zloty later works fully in investments.
- The investing path grows at your chosen return while the debt is serviced with the required instalment.
- We compare net worth (assets minus debt) to highlight the real financial benefit.
The winner and the advantage in zloty are at the very top, and below the form you see the net worth of both strategies side by side. The larger the gap, the stronger the winning strategy.
Adjust debt parameters, expected returns and horizon. Results update instantly, so you can see how a single change – shortening the term or increasing returns – affects your final net worth.
How to read the chart?
Net worth combines rising investments and shrinking (or rising) debt. Line crossings mark when one strategy grows wealth faster than the other. Even if investing wins early on, you will see when debt costs catch up.
A sudden lift of the overpayment line means the mortgage is paid off and the full instalment switches to investing.
- The solid and dashed lines show the net worth of both strategies at the end of each year.
- If the lines cross, the result depends on the horizon: below the chart we give the moment the lead changes.
- Tap a point on the chart to read the net worth of both strategies for that year, or open the data as a table.
When to prioritise debt? / When to favour investing?
When to prioritise debt?
If borrowing costs exceed realistic returns, overpayments almost always win. The calculator shows not only the zloty advantage but also the moment when cashflow is freed for investing.
Monitor the instalment size and amortisation period. A shorter term increases monthly pressure but frees capital sooner.
When to favour investing?
With cheaper debt or high expected returns, investing the surplus can deliver a higher net worth. Watch the break-even threshold – the bigger the spread between returns and interest, the stronger the case for markets.
Use the calculator to test different risk levels. Compare conservative bonds with a dynamic equity portfolio.
How does the algorithm work?
Monthly simulation
We run detailed month-by-month calculations. Debt interest compounds and investments grow at the chosen rate, so the recommendation reflects compound effects and real repayment pace.
The model also captures balance changes from overpayments and updates the next month’s interest automatically.
Net worth focus
We compare assets minus liabilities instead of looking at debt or investments alone. That is the best metric for long-term financial health.
You can see how quickly assets overtake the remaining loan and how much capital works in your favour.
Break-even threshold
We calculate the exact return where both strategies tie. Use it against historical market data or product offers to judge feasibility.
If the threshold is very high, treat investing as an option only with additional safety nets such as an emergency fund.
How to use the recommendation?
Review the recommendation card and the chart. When net worth values are close, factor in comfort and liquidity before deciding.
Consider rate risk and income stability. A strategy that looks best on paper may still need an extra safety buffer.
Example use cases
- Compare mortgage overpayments with investing in an index fund at a chosen return.
- Analyse whether to clear a consolidation loan before building an ETF portfolio.
- Estimate how long it takes to reach financial neutrality while paying down debt and investing simultaneously.
Also check
What next?
Once you know the direction, switch to the full debt vs investing calculator to add dividends, inflation and how returns are split. You will get a fuller picture step by step.
Open full calculator