What this calculator answers
Consolidating a $12,000 debt stack into one 12% loan sounds like a win, but the result depends on the term and the fee. This page compares what you pay today, debt by debt, with what the new loan would cost, and shows both the monthly relief and the total interest bill.
Three debts: $6,000 at 24% paying $250, $4,000 at 15% paying $180 and $2,000 at 27% paying $80.
- Today: $510 a month, $3,943.40 in interest, slowest debt paid off in 38 months
- New loan at 12% for 48 months with a 3% financed fee ($12,360): $325.49 a month, $3,263.34 in interest
Saving: $184.51 a month, $680.06 in interest, and the debt is gone 10 months sooner. A modest but real gain, not a magic fix.
Formulas
n = −ln(1 − balance × r / payment) / ln(1 + r)
r = APR / 100 / 12 Requires payment > balance × r, otherwise the balance never falls. Total interest = payment × n − balance (rounded up to whole months).
PMT = P × [r (1 + r)^n] / [(1 + r)^n − 1]
P = total balance + financed fee n = term in months
Worked example
- Store card: $2,000 at 27% with an $80 payment → n = −ln(1 − 2,000 × 0.0225 / 80) / ln(1.0225) ≈ 37.2 → 38 months
- Credit card: $6,000 at 24% with $250 → ≈ 33.0 → 34 months
- Instalment loan: $4,000 at 15% with $180 → ≈ 26.2 → 27 months
- Today's interest, month by month: $3,943.40
- New loan: $12,000 × 1.03 = $12,360 at 12% over 48 months → PMT ≈ $325.49, interest $3,263.34
When consolidation is a bad deal
A lower rate over a longer term can still cost more. Stretching a $5,000 balance at 6% paying $300 into a 24% five-year loan with a 5% fee lowers the payment and raises total interest. The calculator prints both numbers and warns you when total interest gets worse.
Two hard rules in the model: a payment that does not cover the monthly interest is rejected instead of pretending the debt ends, and the fee is shown separately because it is always paid, even when the loan is.
Related tools
If you want to keep the debts separate and attack them in order, use debt payoff or early loan payoff. To size an affordable payment use the debt-to-income ratio, and to price the business version of the same loan see the business loan calculator.
Three debts ($6,000 at 24% paying $250; $4,000 at 15% paying $180; $2,000 at 27% paying $80) cost $510 a month and $3,943.40 in interest, and the slowest one takes 38 months. A 12% loan for 48 months with a 3% financed fee comes to $325.49 a month and $3,263.34 in interest: $184.51 less per month, $680.06 less interest and 10 months sooner.
No. Stretching a cheap debt into a longer loan can lower the payment and raise total interest. The calculator shows both numbers and warns you when total interest gets worse.
The tool does not simulate that case: if the payment does not beat the monthly interest, the balance never falls without extra money. Raise the payment and calculate again.