Generally, an adjustable-rate mortgage gives you a lower rate than a 30-year fixed-rate loan. As of July 2022, the average 5-year ARM rate was 1.01% lower than the 30-year fixed, potentially saving a homebuyer $180 per month on a $300,000 loan, or about $11,000 in the first five years. These loans could be a great idea for someone who expects their income to increase in the future, or someone who plans to sell, refinance, or pay off the loan within five years.