Interest rate and APR (Annual Percentage Rate) are related but not interchangeable, and lenders are required to disclose both for a reason: they answer different questions. The interest rate tells you the cost of borrowing the principal itself. The APR tells you the cost of the loan overall, including certain fees, expressed as a yearly rate.

What's actually included in each

The interest rate is applied directly to your outstanding balance to calculate the interest charged each period. APR takes that same interest rate and layers in certain additional costs of the loan — things like origination fees, discount points, or certain mortgage closing costs — then spreads that combined cost over the loan term as a single annualized percentage.

Why APR is usually the higher number

Because APR bundles in extra costs, it's typically equal to or higher than the stated interest rate — the gap between the two roughly reflects how much you're paying in fees relative to the loan amount and term. A wide gap between interest rate and APR on a loan offer is a signal to look closely at what fees are being charged, since a low advertised interest rate can hide a less competitive offer once those fees are included.

Comparing two loan offers by interest rate alone can be misleading if one has significantly higher fees — APR is built specifically to make that comparison fairer.

Where this distinction matters most

A practical way to compare offers

When two loan offers have similar terms and loan amounts, comparing APRs gives a more apples-to-apples read on total cost than comparing interest rates alone. That said, APR calculations can still vary somewhat by lender depending on which fees are included, so it's worth asking directly what's built into the number, especially for a mortgage.

Try thisWhen comparing loan offers, write down both the interest rate and the APR side by side for each one. If the gap is unusually large on one offer compared to the others, ask the lender specifically which fees are driving that difference.

Neither number alone tells the whole story on its own, but together they separate "what does borrowing this money cost per year" (interest rate) from "what does this loan cost overall, annualized" (APR) — a distinction worth understanding before signing anything with either number on it.