Data Source & Methodology

AuthoritativeDataSource: Consumer Financial Protection Bureau (CFPB) — Payday loans guidance & research (ongoing), and the standard APR conversion from a periodic finance charge: CFPB: Payday loans.

Tutti i calcoli si basano rigorosamente sulle formule e sui dati forniti da questa fonte.

The Formula Explained

Let:

  • \(P\) = principal (loan amount)
  • \(f\) = fee per \$100 (e.g., \$15 => \(f=15\))
  • \(d\) = term in days for one period
  • \(n\) = number of rollovers
  • \(A\) = one-time admin fee (optional)

Periodic fee amount: \(\displaystyle F = P \times \frac{f}{100}\)

Total fees (including rollovers): \(\displaystyle \text{Fees}_{\text{total}} = (n+1)\,F + A\)

Total repayment (lump sum at final due date): \(\displaystyle \text{Repay} = P + \text{Fees}_{\text{total}}\)

Effective APR (%), annualizing the periodic rate over days: \[ \text{APR}_{\%} = \left(\frac{F}{P}\right) \times \left(\frac{365}{d}\right) \times 100 \] Note: this is the single-period APR. With rollovers, total cost rises linearly with \((n+1)\), while APR per period remains tied to \(d\).

Glossary of Inputs & Outputs

  • Loan amount: Original principal borrowed.
  • Fee per $100: Lender’s periodic charge per \$100 of principal for the term.
  • Term (days): Days until the loan is due.
  • Rollovers: Count of term extensions that add another fee without reducing principal.
  • Admin fee: One-time origination or document fee.
  • Total fees: Sum of all periodic fees across periods plus admin fee.
  • Total repayment: Principal plus total fees.
  • Effective APR: Annualized percentage rate derived from the periodic fee and days.
  • Cost per $100: Total fees divided by (principal/100).

How It Works: A Step-by-Step Example

Example: \(P=\$500\), \(f=\$15\) per \$100, \(d=14\) days, \(n=1\) rollover, \(A=\$0\).

Periodic fee: \(F = 500 \times \frac{15}{100} = \$75\). There are \(n+1=2\) periods, so total fees \(= 2 \times 75 = \$150\). Total repayment \(= 500 + 150 = \$650\). Effective APR (per 14-day period): \(\left(\frac{75}{500}\right) \times \frac{365}{14} \times 100 \approx 391\%\).

Frequently Asked Questions

Why is the effective APR so high?

Because the fee applies to a very short term. Annualizing a 14-day fee leads to a large APR even if the dollar fee seems small.

Do rollovers change the APR?

The per-period APR is tied to the term in days; rollovers increase total fees (and total cost) roughly linearly with each extra period.

Is compounding involved?

Typically no—fees are flat per period. This tool models linear fees plus optional fixed admin costs.

What’s not modeled?

Late fees, NSF fees, collection fees, wage-assignment costs, or state-specific caps are not included.

Where can I learn about protections?

See the CFPB’s consumer guide for payday loans for rights, alternatives, and complaint options.

Tool developed by Ugo Candido. Content verified by the CalcDomain Editorial Board.
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