How to use the "Bi-Weekly Half-Payment" hack to trick your lender's interest daily-accrual algorithm
To most people, a student loan or a mortgage is just a monthly bill. But if you look under the hood of your lender's software, you'll see a relentless math machine: the Daily Interest Accrual Algorithm. In 2026, with federal interest rates for some loans sitting near 7-9% , every day your balance stays high, you are losing money. Here is how to use the "Bi-Weekly Half-Payment" hack to technically outsmart your lender. The Secret: Simple Daily Interest Most student loans use a Simple Daily Interest formula. This means your interest is calculated every single day based on your current principal balance. The formula looks like this: $$(Current Principal \times Annual Interest Rate) \div 365.25 = Daily Interest$$ If you owe $30,000 at 8% , you are being charged roughly $6.57 every single day . When you pay once a month, that daily charge sits there for 30 days, accumulating. How the "Bi-Weekly Hack" Works The "hack" is simple: Instead of making one f...