apr

APR is the sticker rate; APY is what compounding actually does to your money over a year. The gap between them grows with the rate and the compounding frequency — a 24% APR card compounded monthly really charges 26.82%. The simulator lets you crank the frequency and watch the real rate climb away from the quote.

A payday loan's pitch is simple: borrow a few hundred dollars, pay a flat fee, pay it all back on your next payday. The fee sounds small — $15 per $100 is a common example — so it doesn't feel like 'real' interest. But that fee is for a loan lasting roughly two weeks, not a year, and annualizing it the same way every other interest rate gets annualized reveals a true APR that routinely lands north of 300%. Most borrowers can't repay the whole balance on the first due date — that's usually why they borrowed in the first place — so most lenders offer a 'rollover': pay just the fee again, and the loan resets for another two weeks. The principal never moves. Every rollover is a brand-new, full-price fee on the exact same debt. This lesson races that rollover spiral's cumulative fees against a personal loan sized to the same amount, so you can see exactly how fast a 'small' fee turns into real money — sometimes within a single missed due date.