The Key Difference: Interest rate is just the cost of borrowing the principal. APR includes the interest rate PLUS fees, giving you the true annual cost.
Quick Comparison
Interest Rate:
- ✓ Cost of borrowing the principal only
- ✓ Does NOT include fees
- ✓ Makes loans look cheaper
- ✓ Used for monthly payment calculation
APR (Annual Percentage Rate):
- ✓ True cost of borrowing
- ✓ INCLUDES fees and costs
- ✓ Better for comparing loans
- ✓ Required by law on disclosures
What’s Included in APR
APR incorporates various loan costs beyond just interest:
- Origination fees: Lender charges to process the loan
- Discount points: Prepaid interest to lower the rate
- Mortgage insurance: If required for low down payments
- Closing costs: Various fees at loan closing
- Other finance charges: Application fees, underwriting fees, etc.
Real Example: Why APR Matters
Two $300,000 Mortgage Offers:
Lender A:
- Interest Rate: 6.00%
- Fees: $9,000
- APR: 6.28%
Lender B:
- Interest Rate: 6.25%
- Fees: $2,000
- APR: 6.32%
Analysis: Lender A has a lower interest rate but higher APR due to fees. If you keep the loan long-term, Lender A is cheaper. If you refinance or sell within a few years, Lender B’s lower fees make it the better choice.
APR vs APY
Don’t confuse APR with APY (Annual Percentage Yield):
- APR: Used for loans. Doesn’t include compounding effect.
- APY: Used for savings/investments. Includes compounding, showing what you actually earn.
When to Focus on Interest Rate vs APR
Focus on APR when:
- Comparing loan offers
- Planning to keep loan long-term
- Fees vary significantly between lenders
Focus on Interest Rate when:
- Calculating monthly payments
- Planning to refinance soon
- Fees are similar across options
