APR Calculator: Convert Any Loan Fee to a Yearly Rate

Built for any offer on the table: amount, fee, term. Out comes the annualized APR.

Only the APR puts offers with different amounts, fees, and terms on level ground, and this calculator computes it for any fee-based offer. Type in the principal, the flat fees being charged, and the term in days. The tool returns three figures: the annualized APR, the same fees expressed per $100 borrowed, and the full repayment.

The defaults capture the classic two-week shape that Illinois priced out of the market: $45 in fees on a $300 advance over 14 days, which annualizes to about 391% APR, or $15 per $100. Set the same $45 as an installment at the 36% state cap and it buys more than four months of payments on $300. Term length, not the fee alone, drives the annualized number, and the unlicensed market knows it: always compare offers at the same term before comparing anything else.

Two limits keep this tool honest. It prices whichever fee you enter, but a contract can load on charges the advertised APR never mentions, and the number printed in the disclosure you sign is the one that binds. And for covered servicemembers and their dependents, the Military Lending Act caps the cost at 36% APR no matter what a market offer displays.

Amount borrowed, $ Flat fee, $ Term in days

Annualized APR

Per $100 borrowed

Total repayment

The default shows the classic two-week shape: $45 in fees on a $300 advance over 14 days, about 391% APR. The APR disclosure carries the complete ranges.

With the APRs lined up, weigh each total of payments against your budget. The installment calculator handles the payment side, while the request form will price real offers within minutes.

Field notes: tribal loan questions, answered straight

What is APR, in plain terms?

It is the price of borrowing restated as a yearly rate. The tool takes whatever fees an offer quotes and asks this: if the same fees kept repeating at that term for a year, what rate would that be. It remains the only yardstick that sizes up offers with different amounts and terms.

How does a two-week offer compare against an installment loan?

Start with APR, then weigh total cost. The classic $45 on $300 across 14 days is about 391% APR, while a $300 installment at the 36% state cap over six months carries about $27 of interest in total. The first is costlier per dollar per year by an order of magnitude.

Does the APR include every fee?

It covers the fees you entered. A contract may stack origination charges, ancillary products, or returned-item fees on top. Treat the calculator as the baseline and the disclosure you sign as the figure that governs.

What APR counts as high?

For reference, covered borrowers have a 36% ceiling under the Military Lending Act, licensed Illinois installments cap at 36%, and sovereign installment offers usually run 400% to 800% APR across months. Anything between those marks deserves the license lookup before it deserves a signature.

Reviewed by Cal Brooks, Reviewer, credit counseling background. Every fee, cap, and formula on this page was checked against 815 ILCS 123 and the regulator that enforces it.

Last reviewed: 2026-10-15