percent APR Calculator (True Cost of a Loan) star

How the APR Is Calculated

A lender advertises a nominal interest rate, but origination fees, mandatory insurance, and appraisal charges mean the money you actually receive is less than the amount you pay interest on. The tool solves for the rate that makes those two sides match: it takes your loan amount, term, and nominal rate to compute the fixed monthly payment using the standard amortization formula, then subtracts your upfront fees from the disbursed amount to get the net amount received. It then searches — using numerical root-finding (bisection) — for the monthly rate at which the present value of all your payments equals that net amount, and annualizes it with compounding. That annualized rate is the APR.

Worked example: you borrow $20,000 at a 6% nominal annual rate over 5 years (60 months), with a $600 origination fee. The nominal rate gives a monthly payment of roughly $386.66. But you only actually receive $19,400 ($20,000 − $600) to spend, while still repaying the payment schedule calculated on the full $20,000. Solving for the rate that equates $19,400 today to that same 60-payment stream pushes the effective yearly cost up to roughly 6.7-6.9% APR — meaningfully higher than the advertised 6%, purely because of the fee. The tool also reports the effective annual rate (compounding only, no fees, here ≈6.17%) so you can see how much of the total gap comes from fees versus from monthly compounding.

What to Know Before Comparing Loans

APR is always equal to or higher than the nominal rate — it can never be lower, because fees only ever subtract value from what you receive. When comparing two loan offers, the one with the lower APR is the genuinely cheaper loan, even if its advertised nominal rate looks higher on a billboard; a "0% fee, 7% rate" loan can easily beat a "3% fee, 5.5% rate" loan once the fee is folded in.

Only include charges that are conditional on taking the loan: origination or arrangement fees, mandatory credit insurance, appraisal costs tied to underwriting. Do not include costs you would pay regardless — property taxes, optional insurance you would buy anyway, or costs unrelated to the loan's disbursement.

Regulatory APR calculations (EU and US style) use a standard actuarial method, which is what this tool follows; your bank's disclosed APR should land within a few tenths of a percentage point of this result. Small gaps can appear if your lender spreads fees across the term rather than charging them upfront, or uses a different day-count convention. The size of the fee-driven gap also depends on the loan's term: the same fixed fee pushes the APR up more on a short loan than on a long one, because it is amortized over fewer total payments. This calculator is provided for informational and educational purposes only and does not constitute financial advice — verify final terms directly with your lender before signing.