Borrowing decision desk
Loan Calculator
Model the monthly payment, total interest, and term trade-off before you sign a lender offer. The payment is the easy part; the lifetime cost is what tells you whether the loan is actually cheap.
For plain-language APR and amortization context, see the CFPB auto loan key terms.
How Loan Calculation Works
The Loan Calculator computes monthly payments, total interest, and amortization schedules for any fixed-rate loan. Enter the loan amount, interest rate, and term to see exactly how much you will pay each month and how your payments split between principal and interest over time.
Formula
Monthly Payment = P x [r(1+r)^n] / [(1+r)^n - 1] where P=principal, r=monthly rate, n=total payments
Key Features
- ✓Monthly payment calculation for any loan amount
- ✓Complete amortization schedule with principal/interest split
- ✓Total interest paid over the life of the loan
- ✓Compare different loan terms and rates
Pro Tip
Even small interest rate differences matter significantly over long terms. A 0.5% lower rate on a 200,000 USD 30-year mortgage saves over 20,000 USD in total interest. Always shop multiple lenders.
Reference links
Borrowing check
Compare the total loan cost before focusing on the monthly payment
A loan can look affordable month to month while still being expensive over the full term. Use the calculator to compare payment, interest, and term length before accepting an offer or refinancing.
Reference points
Methodology
- Use the loan amount, annual percentage rate, and term length to estimate the amortized monthly payment.
- Compare total interest across terms so a lower payment does not hide a much higher lifetime cost.
- Pressure-test the payment against income, emergency savings, and other fixed obligations before applying.
Practical examples
- A $25,000 loan at 8 percent for 5 years has a payment near $507 and total interest around $5,415.
- A longer term can reduce the monthly payment but usually increases total interest.
- A small rate improvement matters more on large balances or long repayment terms.
Common mistakes to avoid
- Do not compare loans using monthly payment only.
- Do not ignore origination fees, early repayment rules, late fees, or variable-rate risk.
- Do not assume approval terms will match an advertised rate without checking eligibility and credit impact.
When to use it
- Before taking a car, personal, or business loan.
- When comparing a shorter term against a lower monthly payment.
- When the lender quote looks cheap until you add up the interest.
Worked example
A $25,000 loan at 8 percent over 5 years produces a payment near $506.91 per month. Over the full term, you repay about $30,414.59, so roughly $5,414.59 is interest.
How to read the result
A lower monthly payment is not a win if it adds years of interest. Compare the total cost first, then ask whether the payment still fits the rest of your budget.
Practical caveats
Do not ignore origination fees, prepayment penalties, or variable-rate risk. If the payment only works in a perfect month, the loan is too tight.
What to do next
If you can accelerate repayment, move to Loan Payoff Calculator. If the loan is part of a broader debt plan, use Debt Payoff Calculator.
Formula
Monthly payment = P × [r(1 + r)^n] / [(1 + r)^n - 1]
P is principal, r is the monthly rate, and n is the number of payments. The calculation is only useful if the inputs match the loan you will actually sign.
Related tools
Continue your workflow with the next useful tool.
These links stay within the same decision path so you can move to the next calculation without starting over.
How these links are chosen
We only link to closely related pages so each next step supports the same decision.
Report an issue
Found a wrong result, missing option, or confusing explanation? Send it through and we will review the tool.
Report an issue →