High-Yield Savings in 2026: The Interest Rate Math Nobody Explains

I moved $50,000 into a high-yield savings account two years ago and immediately realized I did not understand the math behind my own money. The bank advertised 5.0% APY. I assumed that meant I would earn $2,500 a year. I was close, but the reason I was close and not exact taught me something important about how interest actually works. APY vs APR: They Are Not the Same Number APR is the Annual Percentage Rate, the base interest rate without accounting for compounding. APY is the Annual Percentage Yield, what you actually earn after compounding is factored in. If a bank offers 5.0% APR with monthly compounding, your actual APY is higher than 5.0%. Each month, the interest you earned in previous months starts earning its own interest. The formula is APY = (1 + APR/n)^n - 1, where n is the number of compounding periods per year. At 5.0% APR with monthly compounding (n=12): APY = (1 + 0.05/12)^12 - 1 = 5.116%. On $50,000, that is $2,558 instead of $2,500. The $58 difference does not sound