Extra-payment interest savings: Estimating Interest Saved by Extra Payments
Extra principal payments reduce the balance on which later interest is calculated. Compare the modeled accelerated schedule with the baseline while keeping the original loan assumptions consistent.
Use the Extra-payment interest savings Calculator to enter your own figures and compare the result with the worked example below.
Extra-payment interest savings formula
Savings = Baseline total interest − Accelerated-payoff interest
Worked example
| Item | Example value |
|---|---|
| Loan principal | 10000 USD |
| Annual nominal rate | 6 % |
| Months | 60 months |
| Extra monthly payment | 100 USD |
| Interest saved | 608.620411 USD |
These are illustrative inputs, not current prices, rates or recommended targets. Where a currency is shown, keep all comparable money amounts in the same currency; conversion examples identify the two sides separately.
How to interpret the result
Confirm that the lender applies extra money to principal and check any early-repayment charges. Fees can reduce the net benefit.
Related calculations
Method and further reading
The example follows the FinMathly calculator method. For broader background, see CFPB: Building a budget. The background resource may use jurisdiction-specific terms; it does not replace the assumptions of this calculator.
Featured photograph: Pexels.