Understanding the interest rate for $300 dollar loans is a step in financial wisdom. The interest rate is the cost you have to pay in return for the money lent to you. On GreendayOnline, monetary experts lay out the journey for you. For a loan amount as modest as $300, the interest rate varies from state to state. On average, the fees range between $15 to $30 per $100 borrowed, a small cost for a fast and hassle-free process. Each loan option provides a different rate, offered for you to choose the one that best suits your financial situation.