Interest Rate vs APR: What Is the Difference?

Two numbers appear on every mortgage disclosure, and they answer different questions.

Interest rate

The rate used to calculate your interest charge each month. It determines your payment. Nothing else.

Annual Percentage Rate

A regulated figure that expresses your rate plus certain financing costs as a single annualised percentage. It exists because lenders could otherwise advertise a low rate and recover the difference in fees.

APR generally includes:

• Discount points
• Origination and underwriting fees
• Mortgage broker compensation
• Mortgage insurance premiums
• Prepaid interest

APR generally excludes:

• Title insurance and settlement fees you can shop for
• Appraisal and credit report fees in many cases
• Property taxes and homeowners insurance
• Recording and transfer taxes

Where APR misleads

APR assumes you hold the loan for its entire term. Almost nobody does. Median tenure before sale or refinance is far shorter than thirty years.

This matters because APR spreads upfront costs across 360 months. A loan with $10,000 in points shows a modest APR increase — because the calculation assumes you have thirty years to amortize that cost. If you sell in five, you paid $10,000 for sixty months of slightly lower payments, and the APR badly understated your real cost.

Two further traps:

• Comparing across loan types. An ARM APR is calculated using assumptions about future adjustments that may not hold. Comparing an ARM APR to a fixed APR is not comparing like with like.
• Comparing across terms. A 15-year and a 30-year APR are not directly comparable; the shorter loan concentrates costs into fewer months.

What to compare instead

Total cost over your realistic holding period. Specifically:

1. Take each offer
2. Add all upfront costs you will actually pay
3. Add the payments you will make over the period you expect to hold the loan
4. Subtract the remaining balance at the point you expect to exit

Whichever number is lowest wins, regardless of which has the prettiest rate or APR. The points break-even calculator does the version of this that matters most.

The practical rule

Use APR as a flag, not an answer. A large gap between rate and APR tells you there are meaningful upfront costs worth examining on page 2 of the Loan Estimate. A small gap tells you there are not. Then do the real comparison yourself.

Common questions