APR Calculator
Adjust the inputs below. Results update as you type.
How it works
APR spreads origination fees, points, and other financing charges across the loan term, expressing the true cost as an annual rate. Formula: solve for the rate r in PV = Σ PMT/(1+r)^t over all payment periods. A lower APR means lower total cost even if the nominal rate looks similar. Balloon payments and prepayment penalties can distort APR comparisons.
Input guidance
- Use realistic rates from lender or provider quotes instead of headline averages.
- Model conservative, baseline, and optimistic scenarios before deciding.
- Include recurring real-world costs (fees, taxes, insurance, maintenance) where relevant.
The formula
APR expresses the yearly cost of borrowing including certain fees, not just interest. It is the rate that equates the amount actually received to the stream of payments over the term.
Worked example
A $10,000 loan with a $300 fee repaid as if borrowing the full amount at 8% has an APR above 8% — because you received only $9,700 but repay based on $10,000.
More examples to test
- Conservative case: use a higher interest rate and lower growth assumptions to stress-test affordability.
- Optimistic case: use a lower rate with stable income assumptions to compare upside potential.
How to interpret results
Treat this as a planning model, not a final approval tool. Compare at least two scenarios and focus on total-cost and cash-flow trade-offs.
When this can be inaccurate
Results can diverge due to fees, changing rates, tax rules, lender policies, and behavior changes that simplified models cannot fully capture.
Change history
- July 2026: Quality-reviewed for publication with formula checks and explanatory copy updates.
Site-wide corrections also appear on the corrections log.
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Frequently asked questions
What is the difference between APR and interest rate?+
The interest rate is the cost of the principal alone; APR folds in fees and certain charges, giving a fuller picture of the loan's true yearly cost.
Why compare loans by APR?+
Two loans with the same interest rate can cost different amounts once fees are included. APR makes that comparison fairer.
Does APR include all costs?+
It captures many lender fees but not everything (like late fees or some third-party costs), so still read the full loan terms.
How should I use this result?+
Treat it as a planning estimate. Compare at least two realistic scenarios, then confirm with statements, quotes, or a qualified professional before acting.
How often should I refresh assumptions?+
Refresh whenever rates, income, costs, or policy limits change materially, and before making irreversible commitments.