I'm extremely naive when it comes to finances, so I have a really dumb question for y'all: How/when exactly does interest in a savings account "pay out?" As in, do the banks calculate the, say, 5% based on how much is in the account at the end of the year? Beginning? When you initially open your account? One calendar year from when you initially opened the account? I ask this because there can't a ton of money left after one gets done paying their bills for the entire school year. I apologize for sounding extremely dumb - I was a history major, and can't talk my way out of a wet paper bag when it comes to finances/numbers.