Here's where exactly that money is going:
Discretionary spending: 30 percent. This includes restaurants, alcohol, gifts, museums, parks and any other personal shopping, Adcock tells CNBC Make It.
"Although it is a large chunk of our expenses, it is also the first category that we'll minimize if we ever have to conserve our spending during recessions or other economic uncertainties," says Adcock. It would free up an extra $10,000 a year if they ever needed to decrease their annual expenses.
Groceries: 18 percent. "We are spending more on food now because we can't store as many bulk items, so we find ourselves going to the store more," says Adcock. While downsizing, he and Courtney traded in their 1,600 square-foot house for the Airstream, which they've been living in full-time since April 2016.
Auto: 17 percent. "Our traveling lifestyle requires much more fuel consumption than the average person," says Adcock. "All that diesel adds up."