Millions of Americans don't have enough in savings to cover a major unexpected expense, or continue to pay their bills and medical expenses after a job loss. Experts generally recommend having three-to-six months of living expenses set aside, and an emergency fund calculator can help you determine how much you need to save.

The general rule -- six months of expenses

As a general rule of thumb, it's a good idea to keep six months' worth of your expenses in a readily accessible account. It's important to mention that this doesn't include your 401(k), IRA, or other investments -- this is a separate account that exists for the sole purpose of handling unexpected expenses.

Hand holding hammer poised above pink piggy bank with startled expression.

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When figuring out how much you should have in your emergency fund, be sure to include all of your necessary expenses. This includes your housing and car payments, as well as any recurring bills such as utilities, auto insurance, and others. Also, don't forget to include expenses such as gas and groceries that aren't "mandatory" bills, but still need to be paid.

The "six months" figure isn't set in stone, however. If you have an extremely stable job, great health insurance, and have an overall "low-risk" lifestyle, three months of expenses might be enough. On the other hand, if your employment future is uncertain, or you have health conditions that could result in unexpected expenses, you may want to aim for nine months of expenses, or even more.

The point is that the general rule of thumb for how much you need in an emergency fund should be modified to fit your life. There's no one-size-fits-all magic formula.

Is your emergency fund enough?

According to a report by the Federal Reserve, nearly half of Americans couldn't cover an unexpected $400 expense without borrowing the money or selling something. So there are millions of people who don't have months of living expenses set aside.

To assess your own readiness for unexpected financial burdens, give this calculator a try. You may be surprised at how much three or six months of expenses actually adds up to:

 

* Calculator is for estimation purposes only, and is not financial planning or advice. As with any tool, it is only as accurate as the assumptions it makes and the data it has, and should not be relied on as a substitute for a financial advisor or a tax professional.

If you don't have enough saved right now, or don't think you can get your emergency fund to where it needs to be in the time frame you want, don't panic. The point is to identify the difference between what you have and what you should have, and get yourself on track.

Anything you can save helps

Sure, it would be fantastic for everyone to have enough in their emergency funds to feel completely secure. However, I completely realize that it may not be practical for you to have six months of expenses stashed away, especially if you're young or are just getting started with saving.

The most-important thing you can do is to get started, even if that means adding $50 per month to your emergency fund. Relatively small contributions can really add up over time, and as your savings grows, the range of unforeseen expenses you could handle increases.

For example, if you have $500 in your emergency fund, you don't have to worry about how you would pay for a flat tire on your car, or an unexpected trip to the doctor's office. As you continue to build up your fund, you can add to the list of expenses that wouldn't derail your financial well-being.