What formula does this calculator use?

The standard fixed-rate amortization formula: M = P * r * (1+r)^n / ((1+r)^n - 1), where M is monthly payment, P is principal, r is monthly rate, and n is number of months.

Does it include fees or insurance?

No. This calculator shows principal and interest only. Origination fees, insurance, and taxes should be added separately.

Can I use it for zero-interest loans?

Yes. With a 0% rate, the payment is simply principal divided by number of months.

Why does total interest grow so fast with longer terms?

Each extra month means another month of interest accruing on the remaining balance. A 7-year auto loan can pay 50%+ more interest than a 4-year loan at the same rate, even though the monthly payment is lower.

When should I make extra principal payments?

When the loan rate exceeds your savings/investment return. On high-rate loans (credit cards, payday, personal loans above ~7%), extra principal saves more than the same dollars earn in a savings account.

Loan Calculator

Finance· 37 tools

Free online loan calculator. Enter loan amount, interest rate, and term to see your monthly payment, total interest paid, and total cost. Works for personal loans, auto loans, and any fixed-rate amortizing loan.

Loan Amount ($)

Annual Interest Rate

Term (years)

$489.15

Monthly Payment

$4,349.22

Total Interest

$29,349.22

Total Paid

$26k$19k$13k$6k$-1250

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Disclaimer: For informational purposes only. This is not financial, tax, or legal advice — consult a licensed professional before making decisions.

Frequently Asked Questions

References

Choosing a loan that's right for you — Consumer Financial Protection Bureau

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Frequently Asked Questions

References and sources

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