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A one-time 3% fee can annualize to about 27.4% over 40 days—but that is a simple annualized fee comparison, not automatically the loan’s formal APR. The calculation depends on the fee base, when the money is received, when repayment is due, and how much cash the borrower actually gets.
How a 3% fee becomes about 27% over 40 days
A fee is charged once; APR expresses borrowing costs in relation to the amount and timing of credit and payments over a year. A simple annualization shows why a short-term charge can look much larger when expressed yearly:
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Simple annualized fee rate = fee percentage × 365 ÷ term in days
Using a 3% fee and a 40-day term: 3% × 365 ÷ 40 = 27.375%. Rounded, that is about 27.4%. This calculation assumes the fee is 3% of the chosen principal base and annualizes it linearly using 365 days. It does not establish the formal APR for a particular loan.
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The Consumer Financial Protection Bureau explains the same short-term effect with a different example: a $15 charge per $100 borrowed for two weeks is almost 400% APR. It also compares a 30% APR on $100 borrowed for a year—about $30 in cost—with roughly $1.25 for two weeks. Those examples illustrate how time changes the annualized comparison; they do not make every fee-to-APR calculation interchangeable. CFPB’s payday-loan APR explanation was last reviewed November 25, 2024.
What this calculator’s result means
A calculator using the formula above reports a simple annualized fee rate. It can help explain the effect of term length, but it should not label its output a formal APR unless it calculates the applicable cash flows and follows the rules for that credit product.
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The CFPB describes APR as accounting for interest and fees relative to the amount borrowed and loan duration. Regulation Z frames APR as a measure relating the amount and timing of value received to the amount and timing of payments made. That means a transaction-specific APR can depend on more than the fee percentage and stated term. See the CFPB’s explanation of loan interest rate versus APR and Regulation Z § 1026.22.
Inputs that can change the comparison
- Fee base: A 3% charge might be calculated on the face amount of a loan or on another stated base. The calculator must say which one it uses.
- Money received: If the lender withholds the fee from the advance, the borrower receives less than the face amount. For example, a 3% fee withheld from a stated $1,000 advance leaves $970 in proceeds. A comparison based on $1,000 is different from one based on the $970 actually received.
- Timing: The date funds are available and the dates and amounts of repayments matter to a cash-flow APR. A single 40-day period is not enough to determine APR if payments or charges occur on other dates.
- Annualization convention: The simple illustration above uses 365 days and does not compound the fee. A different formula or product-specific rule can produce a different rate.
For open-end credit, Regulation Z has separate APR-determination provisions and interpretations for transaction charges, including an example involving a charge of 3% of a transaction. Whether those provisions apply depends on the type of credit; see Regulation Z § 1026.14.
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Fee, interest rate, and APR are not synonyms
The interest rate is the rate charged on the borrowed balance. A lender fee is an additional charge, such as an origination fee. APR is a broader measure that can include interest and certain fees, allowing borrowers to compare costs on a more consistent basis. The exact disclosures and calculation rules vary by credit product and applicable law. The CFPB discusses fees on personal installment loans in its consumer guidance on installment-loan fees.
For mortgages, the Closing Disclosure describes APR as “Your costs over the loan term expressed as a rate. This is not your interest rate.” That wording belongs to the mortgage disclosure form; it is not a universal required description for every loan. Regulation Z § 1026.38 sets out the Closing Disclosure requirements.
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How to compare an actual offer
Do not compare a lender’s disclosed APR with a calculator’s simple annualized fee rate as though they were the same measure. For real offers, compare disclosed APRs where available, then check the dollars and timing behind the headline rate.
- How much cash will you receive after any fee is withheld?
- What is the total amount you must repay, and on what dates?
- Which charges are included in the APR, and are there other costs?
- What happens if you pay late, repay early, or extend the loan?
The CFPB advises comparing APRs and says payday lenders must disclose APR and costs before an agreement; requirements can vary by product and applicable law. Its payday-loan APR guidance explains why the disclosed rate can be higher than the interest rate alone.
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