First Financial Refinance Personal Loan Calculator

This calculator estimates the monthly payment and total interest for a fixed-rate personal loan used to refinance debt. Enter the loan amount, APR, and term to see the scheduled payment and the interest paid over the full term; it does not determine whether a lender will approve an application or whether refinancing is suitable for you.

Formula

The calculator uses the standard fixed-payment loan formula. It first finds a monthly payment that repays the principal and interest in equal monthly installments, then multiplies that rounded payment by the number of months to estimate total payments and subtracts the principal to estimate total interest.

• p is the amount borrowed, in dollars.
• apr is the annual percentage rate entered as a percentage per year.
• r is the monthly rate, calculated as apr / 1200.
• n is the term in months, calculated as years × 12.
• pmt is the monthly payment in dollars, rounded to the nearest cent.
• int is estimated total interest in dollars over n scheduled payments.

In symbols, the payment is pmt = round[p × r / (1 − (1 + r)⁻ⁿ), 2]. Total interest is int = pmt × n − p. This calculation assumes the entered APR is the rate used for the loan balance and that the same payment is made every month.

Worked Example

Using the calculator’s default inputs: a $20,000 loan, 8% APR, and a five-year term.

1. Convert the APR to a monthly rate: 8 / 1200 = 0.0066667, or about 0.66667% per month.
2. Convert the term to months: 5 × 12 = 60 payments.
3. Substitute in the payment formula: $20,000 × 0.0066667 / [1 − (1.0066667)⁻⁶⁰] = about $405.53 per month after rounding to cents.
4. Multiply the rounded payment by the number of payments: $405.53 × 60 = $24,331.80 in scheduled payments.
5. Subtract the principal: $24,331.80 − $20,000 = $4,331.80 estimated total interest.

The headline result is a monthly payment of $405.53. Small differences can arise if a lender uses different payment dates, rounding practices, or loan terms than this estimate.

Assumptions

• The interest rate stays fixed for the entire term.
• Payments are equal, made monthly, and treated as scheduled at regular intervals.
• Interest compounds monthly using the APR divided by 12.
• The estimate excludes origination or other fees, taxes, insurance, and any late charges or optional products. It also does not include fees that might be added to the amount borrowed.

How Personal Loan Refinancing Works

Refinancing generally means taking out a new loan to repay one or more existing debts. With a personal-loan refinance, the new loan may pay off an existing personal loan, or a lender may send funds to the borrower to use for repayment, depending on its process. The new loan has its own principal, APR, repayment schedule, and contract terms. A calculator can show the new loan’s scheduled arithmetic, but it cannot establish the amount needed to pay off an old account on a particular date.

For example, someone with an existing balance of $18,000 might compare a new loan amount that covers that payoff with the payment calculated for a proposed term and APR. The exact payoff could differ from the balance shown on a recent statement because interest may accrue between statement and payment dates, and the old agreement may include other amounts. Requesting a dated payoff figure and confirming how proceeds will be applied are separate steps from estimating the new payment.

Comparing a Refinance With the Existing Loan

A lower monthly payment by itself does not show that a refinance will cost less overall. A longer repayment period can reduce the payment while extending the time interest accrues. To make a neutral comparison, collect the remaining balance, remaining number of payments, payment amount, and payoff amount for the current loan, then compare them with the new loan’s amount, term, APR, payment, and any fees. Use lender-provided figures rather than assuming that this calculator includes charges or payoff details.

Keep the comparison on the same basis: consider the remaining scheduled payments on the old loan, rather than its original amount and original term. Also distinguish the new loan’s principal from cash received. If a fee is financed, the amount owed may be larger than the debt being paid off. If a borrower receives extra cash, that portion is additional borrowing and should not be mistaken for savings from refinancing.

Costs, Limits, and Common Mistakes

The calculator’s total interest is based on the rounded payment multiplied by the full number of payments. It is not a complete measure of a refinance’s total cost if fees are excluded or if the payoff timing changes. The actual lender disclosure and account payoff information are needed for exact figures.

• Entering a balance instead of a payoff amount: the amount required to close an existing loan may differ from its displayed principal balance.
• Mixing APR and monthly rates: enter an annual APR such as 8, not 0.08 or a monthly percentage. The formula converts APR to a monthly rate.
• Ignoring the term: a payment estimate depends on both rate and duration. Compare the full scheduled repayment, not only the monthly amount.
• Leaving fees out: the result does not include fees or show whether they are paid separately or added to the loan.
• Assuming a fixed schedule applies to every offer: this formula models equal monthly installments at a fixed rate, not variable rates, irregular payment dates, or changing balances caused by missed or extra payments.

The APR and term fields are inputs for illustration, not claims about rates or terms available from any lender. Obtain actual proposed terms directly from the lender and check how its disclosure treats fees, payment dates, and payoff funds.

Frequently Asked Questions

What does refinancing a personal loan mean?
It means replacing an existing debt with a new loan, subject to the new loan’s terms. The new proceeds may be used to repay the old balance, but the process and payoff handling depend on the lender.

Can refinancing lower my monthly payment?
A different APR, loan amount, or repayment term changes the calculated payment. A longer term can lower the scheduled monthly amount while increasing the number of payments, so the payment alone does not show total cost.

Does this calculator include refinance fees?
No. It calculates payment and interest from the amount, APR, and term entered. Add any applicable costs only if you are separately modelling them in the loan amount; confirm actual charges in the lender’s disclosure.

Should I enter my current balance or payoff amount?
For estimating a new loan intended to clear an existing account, use a carefully verified amount needed for the new borrowing calculation. Ask the current lender for a dated payoff figure because a statement balance may not equal the amount due on the payment date.

Does applying to refinance guarantee approval?
No. This calculator performs arithmetic only. It does not evaluate an application, predict approval, or represent any lender’s criteria.

This result is an estimate, and the lender’s disclosure gives the exact figures.

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in p | Loan amount | $ | 20000 | 1 | 100000000
in apr | Interest rate (APR) | % | 8 | 0.01 | 100
in yrs | Loan term | years | 5 | 0.0833 | 50
out pmt | Monthly payment | $ | round(p * (apr / 1200) / (1 - (1 + apr / 1200) ^ -(yrs * 12)), 2) | 2
out int | Total interest | $ | pmt * yrs * 12 - p | 2