Loan Calculator Guide: Reading Your Payment and Total Cost

How to read a loan calculator's payment, total interest, and total cost figures, and what an origination fee actually does to your loan.

A loan calculator's job is simple on the surface: amount, rate, and term go in, a payment comes out. The three numbers worth actually reading are the payment, the total interest, and the total cost — and they answer three different questions.

Payment answers "does this fit my budget"

This is the fixed amount due each period for the life of the loan. It's calculated so the balance hits exactly zero after your last payment, assuming the rate never changes. Two loans with similar payments can still cost very differently overall, which is why payment alone isn't enough to compare offers.

Total interest and total cost answer "what does this actually cost"

Total interest is every interest charge added up over the full term. Total cost adds the principal back in, plus any origination fee, giving you the real number: everything you'll hand over before the loan is paid off. A lower rate with a higher fee can cost more than a higher rate with no fee — total cost is what settles that comparison, not the headline APR.

What the origination fee does and doesn't do

An origination fee is a one-time charge some lenders add for issuing the loan. This calculator adds it straight to your total cost as its own line item, rather than folding it into the payment or trying to back-solve an adjusted APR — that kind of blended rate depends on details (is the fee financed or deducted from your payout?) that vary by lender, so a single calculator number would be a guess dressed up as precision.

Use the Loan Calculator to run your own numbers, or the Amortization Calculator if you want to model paying extra toward principal.