This APR calculator finds the annual percentage rate of a fixed-rate installment loan with upfront fees. Enter the loan amount, annual rate, term in months, and fees. It computes the monthly payment, subtracts the fees to get the amount financed, then solves for the yearly rate at which that payment repays the amount financed, the same method lenders use for Truth in Lending APR.
Borrowers use it to compare offers when one lender quotes a lower rate but higher fees. Official disclosures can still differ from this educational formula. If you know only the payment, the interest rate calculator finds the rate.
APR is the yearly cost of a loan including certain fees, so it is equal to or higher than the interest rate. Example: a $10,000 loan at 6% for 36 months has a $304.22 payment. If $300 in fees is taken from the loan, you receive $9,700 but still repay $304.22 a month, so the APR is about 8.06%. With no fees, the APR equals the 6% rate. Under Regulation Z, a disclosed APR on a regular loan is considered accurate if it is within 1/8 of a percentage point of the true figure.
How fees raise APR
| Loan | Rate | Term | Fees | Payment | APR |
|---|---|---|---|---|---|
| $10,000 | 6% | 36 mo | $0 | $304.22 | 6.00% |
| $10,000 | 6% | 36 mo | $300 | $304.22 | 8.06% |
| $10,000 | 6% | 60 mo | $300 | $193.33 | 7.27% |
| $10,000 | 5.5% | 36 mo | $500 | $301.96 | 8.97% |
| $20,000 | 8% | 60 mo | $600 | $405.53 | 9.30% |
Note: the same fee adds less APR on a longer term. Sources: CFPB “rate vs APR” https://www.consumerfinance.gov/ask-cfpb/what-is-the-difference-between-a-loans-interest-rate-and-its-apr-en-733/ (last reviewed 28 Aug 2026): APR includes the interest rate plus fees such as origination charges. Reg Z 12 CFR 1026.22 https://www.consumerfinance.gov/rules-policy/regulations/1026/22/: 1/8 of 1 percentage point tolerance for regular transactions.
How the APR is calculated
Payment equals PMT(loan amount, rate, months). Amount financed equals loan amount minus upfront fees. APR is the annual rate r for which the present value of the payments equals the amount financed: amount financed = payment × (1 − (1 + r/12)^−months) / (r/12). There is no closed form, so the calculator solves for r numerically.
This is the actuarial method in Regulation Z for a regular loan with equal monthly payments. Loans with irregular payments, odd first periods, or mortgage-specific charges can disclose a slightly different APR.
Worked example
Principal $10,000, rate 6 percent, 36 months, fees $300. Payment is about $304.22. You receive $9,700 after fees but repay $304.22 for 36 months, so the APR is about 8.06 percent, compared with the 6 percent note rate.
| Input | Value |
|---|---|
| Principal | $10,000 |
| Rate | 6% |
| Months | 36 |
| Fees | $300 |
| Amount financed | $9,700 |
| Payment | $304.22 |
| APR | 8.06% |
How to use the fields
- Loan amount is the principal on the note, before fees are subtracted.
- Rate is the nominal annual interest rate on the note.
- Months is the amortizing term.
- Fees are upfront finance charges, such as origination fees, paid at closing or taken from the loan.
Reading results beside payment
Always look at the monthly payment and total interest with the APR. A short loan can show a different APR story than a long loan with the same fees. For payment focused checks, open the loan calculator.
Common mistakes
- Expecting an exact match with a mortgage Loan Estimate, which can include charges this calculator does not model
- Leaving out fees that are required to get the quoted rate
- Rolling fees into principal and also entering them in the fees field
- Comparing APRs for loans with very different terms without reading payment
Why lenders quote rate and APR differently
The note rate drives the amortizing payment. APR disclosures aim to express a broader finance charge idea for comparison shopping. This calculator spreads the fees over the term by solving for the rate, so a lender’s disclosed APR for the same loan should land within 1/8 of a percentage point.
When two banks show similar rates and very different fees, APR often flips the ranking. When fees are tiny, payment and rate dominate the decision instead.
What to put in the fees field
Origination fees, underwriting fees labeled as finance charges, and similar lender charges belong in many comparisons. Third party appraisal costs sometimes sit outside APR and sometimes inside, depending on rules and products. If you are unsure, run the comparison twice: once with only lender fees, once with every upfront cost you must pay to close.
- Do not double count fees already added into principal unless that matches how interest is charged.
- Keep term months identical when comparing two APRs.
- Read monthly payment every time, not only APR.
Limitations
Precomputed interest, odd day counts, and mandatory insurance products need lender math. Mortgage APRs follow extra Reg Z rules (and different tolerances for irregular loans); use your Loan Estimate. Treat the output as a planning aid when screening offers.