Core Concepts
Every loan advertisement leads with the interest rate. APR is what you should actually look at. Here's the difference and why it matters every time you borrow money.
APR stands for Annual Percentage Rate. It's the yearly cost of a loan expressed as a percentage, and it includes the interest rate plus most of the fees associated with the loan. The key distinction: the interest rate only tells you the cost of borrowing the principal. The APR tells you the total annualized cost including fees.
Lenders are required by the Truth in Lending Act to disclose APR on consumer loans. The requirement exists specifically because interest rates alone are easy to game. You can have a low interest rate with high fees, and the APR exposes that.
Consider two mortgage offers. Lender A offers 6.25% with no points and $3,000 in lender fees. Lender B offers 6.0% with one point (1% of the loan amount, or $2,000 on a $200,000 loan) and $4,500 in fees.
Looking at just the rate, Lender B looks cheaper. But the APR on Lender B, after incorporating those fees, might come out to 6.4%. Lender A's APR, with lower fees, might be 6.55%. That comparison is meaningful, but it's the rate comparison that's misleading.
In this specific scenario: if you're holding the loan long-term, the lower base rate might actually win despite the higher APR, because the monthly payment savings compound over 30 years. But if you might refinance in 5-7 years, you'd never recoup those upfront fees. APR assumes you hold the loan to term. That assumption doesn't always hold.
Loan A: $10,000 personal loan, 8% interest rate, $300 origination fee, 36-month term. Monthly payment: $313. Total repaid: $11,268. APR: approximately 10.0%.
Loan B: $10,000 personal loan, 9% interest rate, no origination fee, 36-month term. Monthly payment: $318. Total repaid: $11,448. APR: approximately 9.0%.
Loan A has a lower interest rate but a higher APR due to the fee. Loan B costs more per month but slightly more total. Which is better depends on your priorities, but the comparison is only possible because you're looking at both the rate and the APR.
A two-week payday loan for $400 with a $60 fee. That fee looks modest. But annualized: $60 fee / $400 principal = 15% for two weeks. Multiply by 26 (the number of two-week periods in a year) and you get an effective APR of 390%. Lenders aren't required to express payday loan costs as APR in all jurisdictions, but the math is the math.
Simple. Interest rates are lower numbers than APRs. A 5.875% interest rate on a mortgage sounds more attractive than a 6.2% APR, even though the APR is the more complete picture. Marketing leads with what looks best.
Additionally, the APR calculation requires assumptions about loan term. For adjustable rate products or revolving credit, the APR is harder to calculate and easier to obscure. This is why credit cards disclose APR but it still doesn't capture costs like annual fees, late fees, or the impact of carrying a balance at minimum payments.
APR is a useful comparison tool, not a complete picture:
Compare APRs on loans with similar terms. Don't compare the APR on a 30-year mortgage to the APR on a 15-year mortgage without adjusting for the different contexts. Use APR as your primary comparison tool when evaluating multiple offers, but also look at total cost of loan and monthly payment to get the complete picture.
The blog post on APR vs. interest rate expands on this topic. Our loan transparency guide covers what lenders must disclose by law, including APR.