After one year at a 5% APY, $1,000 would earn $50. Note that the amount of interest earned each month could vary a bit based on the compounding rate, such as how with some accounts, interest compounds daily, while some are compounded annually. While that compounding frequency affects the underlying interest rate, either way, a 5% APY tells you that after a year, the account would grow from $1,000 to $1,050.