Tools
Repay, Invest or Save Calculator
Compare three practical choices for extra cash: repay your mortgage faster, invest in equities, or keep the money in savings.
This calculator is built for real trade-offs. It combines loan-interest savings and investment growth into one comparable net-benefit view, so you can see what your assumptions imply over the same period.
Good for: deciding what to do with monthly surplus cash and one-time amounts without guessing.
Try this: test 100% repayment, 100% investing, and a mixed allocation to see how sensitive the result is to your assumptions.
Inputs
25.0 years (300 months)
The horizon is capped to the loan term (max 25 years).
Allocation
Scenario comparison
Highest net benefit with these assumptions: 100% stocks
| Scenario | Net benefit | Invest/savings pot at horizon | Interest saved | Loan term reduction |
|---|---|---|---|---|
| Chosen allocation | +11 748 € | 29 118 € | 3 630 € | 45 mo |
| 100% repayment | +9 075 € | 0 € | 9 075 € | 92 mo |
| 100% stockshöchster | +17 599 € | 52 599 € | 0 € | no reduction |
| 100% savings | +5 394 € | 40 394 € | 0 € | no reduction |
Year-by-year breakdown for chosen allocation
Yearly incremental effect = stocks + savings + loan-interest savings (taxes excluded).
| Year | Stocks | Savings | Loan savings | Total / year | Cumulative net benefit |
|---|---|---|---|---|---|
| 1 | +178 € | +32 € | +102 € | +312 € | +312 € |
| 2 | +274 € | +48 € | +154 € | +476 € | +788 € |
| 3 | +378 € | +64 € | +208 € | +650 € | +1 437 € |
| 4 | +488 € | +80 € | +264 € | +833 € | +2 270 € |
| 5 | +606 € | +97 € | +323 € | +1 027 € | +3 297 € |
| 6 | +733 € | +115 € | +384 € | +1 232 € | +4 529 € |
| 7 | +868 € | +133 € | +447 € | +1 448 € | +5 977 € |
| 8 | +1 013 € | +151 € | +513 € | +1 677 € | +7 654 € |
| 9 | +1 168 € | +170 € | +582 € | +1 919 € | +9 573 € |
| 10 | +1 333 € | +189 € | +653 € | +2 175 € | +11 748 € |
Assumptions and limits
This tool is illustrative and does not constitute investment advice. Returns, rates, taxes and costs are uncertain. Always verify current provider terms and your own situation.
Need the decision framework first?
Use the calculator after you understand the role of debt cost, cash reserves and investing horizon. Read the guide