How much should you actually save for emergencies?

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How much money to set aside for emergency savings is more of a moving target than many consumers realize.

Almost a third of Americans are still at square one, with 29 percent telling they have no emergency savings. That's up from 26 percent last year and the highest rate in five years of queries.

Failing to save is a big misstep, even when there are competing financial goals like saving for retirement or paying down credit card debt. "There are always these things that pop up, that don't normally happen but affect your finances," said certified financial planner Clark Randall, founder of Financial Enlightenment in Dallas. "If you're always handling those with credit, then you're never really achieving what you want to do."

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Only 22 percent of the 1,000 adults surveyed by said they had enough to cover expenses for six months—a five-year low. Another 15 percent said they have savings equivalent to three to five months, and 21 percent can cover less than three months.

But not all of the consumers with less than six months' worth of expenses saved are in the red zone. And even some of those six-month savers may not have enough. "That three-to-six-months rule is just a guide," said certified financial planner Janet A. Stanzak, chair of the Financial Planning Association's board of directors. The ideal emergency savings goal might be as little as three months or as much as two years of expenses, financial advisors say. It all depends on your personal situation.

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Several factors could shift the goal amount in one direction or another:

Job security. The less certain your income, the more flush emergency savings should be, said certified financial planner Carolyn McClanahan, director of financial planning at Life Planning Partners in Jacksonville, Florida. By that measure, freelancers, entrepreneurs and workers relying on commission should plan for a bigger cushion, she said.

Skill marketability. It's less common these days to hear stories of consumers out of work for a year or more, said Stanzak, but it does happen. "You have to look at those job possibilities," she said. If your work is highly specialized and there are few openings in the field, that merits saving more to hedge against the possibility of a long stretch of unemployment. Ditto if you're an older worker who might face age discrimination in a job search.

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Possible emergencies. Job loss is one reason to have a safety net in place (hence the first two considerations), but it's not the only financial crisis families come up against. People with health concerns might want to err on the side of caution with a bigger cushion, as should homeowners, said Randall. "If you rent an apartment and the air-conditioning goes out, that's the landlord's responsibility," he said. "If you own, that repair is out of your pocket."

Other assets. "Do you have other means you could easily tap and pay back, without it hurting you?" asked McClanahan. If so, you may be able to get by with less of a cash emergency fund. An existing home equity line of credit might supplement savings, for example, or investments in a brokerage account, she said. But hands off retirement savings: "I would not ever borrow against your 401(k)," she said.

Household income. If both partners in a married couple work, they can have more wiggle room in how much to save, Stanzak said—emergency savings may only need to cover one person's share of the bills. Other regular sources of income from side gigs or investments could also reduce needs.

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Comfort level. There's something to be said for peace of mind, said Randall. "For me, having three months for an emergency fund set aside, that would scare me," he said. His personal preference is to have six to 12 months' worth set aside. Retirees should have an even bigger cushion—as much as 24 months, he said—to help avoid panic-induced moves if the market tumbles. "That gives you time before you need to take something at a loss," he said.

Monthly expenses. A month's worth of expenses doesn't necessarily mean the entire budget. Savings should be enough to cover at least your necessary expenses like the mortgage, groceries and utilities, said McClanahan. Ideally, you'd save even more to cover unexpected extras, she said. For example, job hunting costs or extra expenses incurred to care for a family member experiencing a medical emergency.