APR vs Interest Rate — What’s the Difference?

What this calculator is

The Mortgage Calculator is an interactive tool inside GetCalcMaster. It’s designed to help you explore scenarios, understand formulas, and document assumptions.

Key features

• Interest rate affects monthly payment
• APR includes some fees and spreads cost over time
• Compare offers using consistent assumptions

Formula

Interest rate: cost of borrowing on the principal only
APR: broader yearly cost including certain fees, expressed as a rate

Quick examples

• Loan with 6.0% interest rate + upfront fees can have APR > 6.0%
• APR is most useful for comparing two offers with different fee structures
• For very short holding periods, APR comparison can differ from long-term cost

Verification tips

• Use APR to compare loans on a more apples-to-apples basis (fees included).
• Confirm which fees are included/excluded in the APR calculation.
• Your actual cost depends on how long you keep the loan and whether you refinance.

Common mistakes

• Assuming APR equals the interest rate (it often differs).
• Comparing APRs across loans with different terms without context.
• Ignoring points/credits that change the effective cost.

How to use it (quick steps)

1. Enter loan basics: home price (or loan amount), down payment, interest rate, and term.
2. Optionally expand advanced inputs (extra payments, PMI/escrow, ARM scenarios, and fees).
3. Review monthly payment, payoff timeline, total interest, and the amortization schedule.
4. Export your scenario for record‑keeping, then verify details with lender disclosures and official documents.

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FAQ

Tip: For reproducible work, save your inputs and reasoning in Notebook.