This couple retired in their 30s—here's exactly what their budget looks like

This couple retired in their 30s and travels full-time in an Airstream trailer

Steve Adcock, 36, and his wife Courtney, 32, set aside up to 70 percent of their IT salaries in order to retire early.

Shortly after quitting their jobs, the couple left their home-base in Tuscon, Arizona, in order to travel the country full-time in a 30-foot Airstream trailer.

Their lifestyle "no longer depends on any source of income," Adcock writes on his blog, ThinkSaveRetire. "Any money that we bring in by working for fun is icing on the cake."

To make sure their savings last through retirement, the Adcocks plan to spend about 3 percent of their total net worth each year. That comes out to about $33,000 per year — or, $2,800 per month.

Steve and Courtney Adcock retired in their 30s
Courtesy of Steve Adcock

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."

Health: 11 percent. This includes health insurance and any medications they buy.

Campground fees: 10 percent. These fees vary month-to-month, as sometimes they're not parking the Airstream on campgrounds. If they are using a campsite, fees are never more than $400 a month, says Adcock.

Home: 9 percent. This category includes propane, maintenance and insurance on the Airstream.

Pets: 3 percent. The Adcocks travel with their two rescue dogs, Patti and Penny.

Other: 2 percent. This includes memberships, such as the one they maintain to Passport America, a camping membership that offers discounts at certain campgrounds and to Adcock's gym.

How this couple saved over $1 million in retirement savings to retire by 43

The couple also maintains a "sizable emergency fund to account for any large unanticipated expenses," Adcock tells CNBC Make It. "Those expenses would be provided for outside of our regular spending budget and would not be represented in these percentages."

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