APR Calculator

About the APR Calculator

An APR calculator reveals the true annual cost of any loan by incorporating origination fees, closing costs, and other charges into a single comparable percentage — the Annual Percentage Rate. The stated interest rate on a loan only tells half the story; lenders frequently add 1-5% origination fees, broker fees, points, or other charges that dramatically increase the actual cost of borrowing. APR standardizes all of these costs into a single annualized figure, making it the only fair basis for comparing loan offers from different lenders. Under the US Truth in Lending Act and equivalent regulations in the UK, Canada, and Australia, lenders are required to disclose APR — but many consumers do not know what it means or how to verify whether the disclosed APR is correct. Our free APR calculator computes the true APR from first principles: enter the loan amount, nominal interest rate, term, origination fee percentage, and any flat fees, and the calculator solves for the precise APR using the same discounted cash flow iteration that regulators mandate. Use it to verify lender disclosures, compare loan offers, and understand the true annual cost of borrowing.

How It Works

APR is the discount rate r that makes the present value of all loan payments equal to the net loan proceeds (amount received after all fees are deducted). Net proceeds = Loan amount - Origination fee - Flat fees. Monthly payment is calculated on the full loan amount (before fees) using the standard amortization formula: PMT = P × [r_nominal(1+r_nominal)^n] / [(1+r_nominal)^n - 1]. APR is then solved iteratively (Newton-Raphson): find r_APR such that PMT × [1-(1+r_APR)^-n] / r_APR = Net proceeds. APR = r_APR × 12 × 100. Example: $20,000 loan at 7% nominal rate, 48 months, 2% origination fee ($400), $100 processing fee. Net proceeds = $20,000 - $400 - $100 = $19,500. Monthly payment = $20,000 × [0.005833 × (1.005833)^48] / [(1.005833)^48 - 1] = $478.92. Solve for r_APR: PMT × [1-(1+r_APR)^-48] / r_APR = $19,500. Result: r_APR ≈ 0.007023/month × 12 = 8.43% APR. The 7% nominal rate becomes 8.43% APR once fees are included — a $500 difference in fees on a 4-year loan raises the effective cost by 1.43 percentage points.

Tips & Best Practices

• ✓Always compare loan offers by APR, not nominal rate. A loan at 6.5% with a 3% origination fee has a higher APR than a loan at 7.0% with no fees for terms under about 8 years — the fee front-loads the true cost.
• ✓For mortgage loans, APR includes origination fees, discount points, and most closing costs but excludes title insurance, appraisal, and recording fees. This means mortgage APR understates the true total cost, but still provides a better comparison metric than the interest rate alone.
• ✓Short-term loans amplify the fee impact: a 2% origination fee on a 12-month loan raises APR by approximately 3.7%. The same fee on a 60-month loan raises APR by only 0.76%. Short-term borrowers should scrutinize fees far more carefully than long-term borrowers.
• ✓Payday loan APR: a $15 fee on a $100 two-week payday loan = 15% fee for 14 days. APR = (15/100) × (365/14) = 391%. The APR calculation makes payday loan costs viscerally clear in a way that the nominal fee amount does not.
• ✓0% APR promotional periods: if a loan charges 0% for 12 months and then reverts to 24.99% with no fee, the APR for the full promotional period is genuinely 0% during that window. But deferred interest products — which charge retroactive interest from day 1 if the balance is not paid in full — are not 0% APR products despite advertising.
• ✓UK APR regulations: UK lenders must display a representative APR based on a loan of £10,000 over 5 years, applicable to at least 51% of customers. This representative APR may be lower than what you personally are offered — always get a personalized quote.

Who Uses This Calculator

Borrowers comparing loan offers from multiple lenders on an equivalent basis. People verifying that the APR disclosed by a lender matches the fees and rate they were quoted. Small business owners evaluating financing costs for equipment or working capital loans. Consumers identifying the true cost difference between cash rebate and low-interest financing offers. Financial literacy educators illustrating how fees transform stated interest rates into higher effective costs.