Consolidation Loan Investment Calculator
Consolidating debt can lower your monthly payment. This calculator shows what investing that monthly saving — instead of spending it — could grow into.
A worked example
Running this tool on current national benchmarks (Federal Reserve / Freddie Mac via FRED (St. Louis Fed)) — swap in your own numbers to see how the result moves.
- Total debt to consolidate
- $25,000
- Current total monthly payment
- $700
- Consolidation loan rate
- 11%
- Consolidation term (years)
- 5
- Investment return
- 7%
from $156.44/mo saved over 5 years
- New monthly payment$543.56
- Monthly saving$156.44
- Total invested$9,386
How the invested monthly savings grow to changes with total debt to consolidate
Holding the other inputs at the example above, here is how the result moves as total debt to consolidate changes.
| Total debt to consolidate | Invested monthly savings grow to | New monthly payment |
|---|---|---|
| $15,000 | $26,766 | $326.14 |
| $20,000 | $18,983 | $434.85 |
| $25,000 | $11,200 | $543.56 |
| $40,000 | $0 | $869.70 |
| $50,000 | $0 | $1,087.12 |
The math behind it
First the calculator amortizes a consolidation loan at its rate and term to find the new monthly payment, then subtracts it from your current payment to get the monthly saving. It assumes you invest that saving every month at your chosen return, compounding monthly over the loan term. The result is what the invested difference grows to — splitting it into the amount you contributed and the investment growth on top.
Assumptions & limits
- The monthly saving is the current payment minus the consolidated payment; if that is zero or negative, there is nothing to invest.
- You invest the full saving every month and never withdraw it.
- The investment return is a fixed annual rate compounded monthly.
- The investing horizon equals the consolidation term.
- Returns are illustrative and not guaranteed — real markets fluctuate.
Common questions
Is investing the saving better than paying the debt off faster?
It depends on the numbers. Investing the difference builds wealth only if your expected after-tax return beats the loan's interest rate; otherwise, putting the saving straight back onto the debt is the surer win. This tool shows the invest-the-difference upside, but a guaranteed rate saved by paying down debt often outperforms an uncertain market return.
What return should I assume?
Be conservative. A broad stock index has historically averaged in the high single digits before inflation over long periods, but any single stretch can be much lower or negative. Enter a rate you are comfortable defending, and remember the calculator's growth is an illustration, not a promise.
What if consolidating does not lower my payment?
Then there is no monthly saving to invest, and the calculator says so. The whole premise depends on the new payment being smaller than your current one; if it is not, look for a lower rate or a different option before assuming any investable difference.