Two rates answer different questions
The interest rate is used to calculate interest on the outstanding loan balance. For a fixed-rate installment loan, it helps determine the scheduled principal-and-interest payment. APR is a broader annualized measure of borrowing cost that incorporates certain financing charges as well as interest. For mortgages, points and certain lender or broker charges can affect APR.
A payment example
Consider a hypothetical $12,000 loan with a 0% interest rate and a one-year term. Principal payments are $1,000 per month. If the borrower also pays an origination charge, the loan is no longer cost-free even though its interest rate is zero. That fee changes the borrowing cost; our simple payment calculator does not compute the resulting APR.
Use the correct input
Enter the contractual interest rate in FinMathly’s loan and mortgage calculators. Substituting a fee-inclusive APR in the interest-rate field can misstate the payment. Compare the lender’s disclosed APR separately, alongside the fees, term, and payment schedule.
Compare similar offers
A shorter loan and a longer loan can have different cash-flow tradeoffs even when one rate looks lower. Check the actual charges and how long you expect to keep the loan. Adjustable rates, early repayment, and financed fees require closer attention than a single percentage can provide.
Further reading
CFPB: Mortgage interest rate and APR
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