Over a quarter of American adults believe they can live on Social Security alone in retirement. And they can -- if they wish to eat poorly, live in substandard housing, and barely survive in general.

The average American senior citizen collects just $17,748 a year in Social Security benefits. Even if you assume that two people are living in a household together, their combined $35,496 from the Social Security Administration (on average) leaves them woefully behind what the average American spends in a year.

An older couple walks on a beach.

Social Security won't cover the average American's expenses in retirement. Image source: Getty Images.

How much does the average American spend?

Many people assume that their costs will decrease when they retire. That can be true: If you move from Manhattan to Central Florida, for example, your housing costs could decrease dramatically, as would some other expenses. The same would be true if you stay in the same market but downsize your home, opt to eat out less often, or go from two cars to one.

It may be possible, even acceptable, for many retirees to have less income than they did when they worked. For most, however, Social Security alone won't be enough to get by, and it will be well less than what the average American spends each year, according to 2018 data shared by Statista.

Expense Cost
Housing $20,091.00
Transportation $9,761.00
Food $7,923.00
Personal insurance & pensions $7,296.00
Healthcare $4,968.00
Entertainment $3,226.00
Other $2,030.00
Cash contributions $1,888.00
Apparel & services $1,866.00
Total $61,224.00

Data source: Statista.

As you can see from the total, one person collecting Social Security with no other income would be woefully behind the average. It gets somewhat better for a couple if they're both collecting the $17,748 average, but they would still have $25,728 less than the average spending total.

These numbers aren't set in stone. Averages can be misleading, as the biggest spenders may throw the numbers off somewhat. Still, the average cost of renting a one-bedroom apartment came in at $1,230 in Dec. 2019, according to a report from Zumper, which tracks rent in the top-100 metro areas by population.

That means that, on average, you would have to spend $14,760 -- nearly all of one person's average Social Security income -- on rent. Even if you opted for the cheapest city tracked (Akron, OH, at $630 a month) you would still be spending $7,560 on rent, over 40% of your income.

In reality, the average American retiree spends $16,273 on housing, which includes rent or mortgage payments, insurance, and, if applicable, property taxes, maintenance, and repairs. It doesn't include utilities or household amenities like cable and internet service.

Don't expect to get by on Social Security

You may plan to spend your retirement years living in a tent eating ramen noodles. That's an option -- but it does not factor in potential problems like unexpected healthcare woes, or the fact that even campgrounds charge rent.

The reality is that you want to make a retirement plan and adjust it every few years. Even if you plan to dramatically reduce your expenses, you don't want to be in a position where you have to do that or you will run out of money.

Plan for the worst. Expect that costs will rise and that unexpected bills will occur. If you have "too much" money, that gives you options and offer you a lot more freedom than having too little.

It's also important to have an emergency fund in retirement. This is money you've set aside to pay for things you may not have thought of. Ideally, this money will never be needed but it's always smart to plan for every reasonable contigency, especially when you are no longer receiving regular paychecks.