THE NUMORIX GUIDE
How to use the Debt Consolidation Calculator
Last reviewed September 14, 2026
What this calculator does
The current-debt side solves each debt's payoff months from balance, payment, and APR, sums payments and interest, and uses the longest debt as the comparison horizon.
Formula and method
The current-debt side solves each debt's payoff months from balance, payment, and APR, sums payments and interest, and uses the longest debt as the comparison horizon. The consolidation side adds percentage and fixed loan fees to the entered loan amount, amortizes that larger principal at the new rate and term, and compares the two interest totals. The displayed APRs are simplified interest-to-principal annualizations.
Variables and inputs
Enter one or more current debts with name, balance, monthly payment, and APR. Enter consolidation loan amount, interest rate, term years and months, percentage fee, and fixed dollar fee. All money values are dollars and rates are percentages.
Worked example
For a $16,000 consolidation loan with a 2% fee and no fixed fee, the fee is 16,000 x 0.02 = $320 and financed principal is $16,320. At 8% for 42 months, the monthly rate is 0.08 / 12 and the payment formula produces roughly $443 per month; total scheduled payments are about 42 x 443 = $18,606 before rounding.
How to interpret the result
A lower monthly payment can come from a lower rate, a longer term, or both. Compare total interest, total cost including fees, payoff month, and the current payment burden. A positive displayed saving is only a saving under the entered payoff assumptions.
Common mistakes to avoid
Include every fee that will be financed or paid upfront, and do not compare the new interest total with old interest while forgetting the new loan fee. Ensure each old debt's payment is high enough to amortize it; the engine does not provide a robust validation message for every invalid combination.
Assumptions and limitations
The current APR comparison is a simplified annualization rather than a regulatory APR calculation. It assumes fixed rates and payments, excludes new borrowing and behavior after consolidation, and uses a longest-current-debt horizon rather than a complete cash-flow timing comparison.