How big should your emergency fund be, and how long will it take?

The usual advice is to keep three to six months of essential expenses in cash. For a household with $4,200 in monthly essentials, that means $12,600 to $25,200. Saving $400 a month, the three-month cushion takes under two years to build.

What an emergency fund is for

An emergency fund covers the expenses you can't avoid when something goes wrong: a job loss, a medical bill, a car repair, a broken furnace. Without one, those costs usually land on a credit card at 20% or more, and a one-time problem becomes a debt that lasts years.

It is not a vacation fund or a down payment fund. Keep it separate so it's there when you need it.

Count essentials, not your whole budget

The target is based on the bills you would still have to pay if your income stopped:

• Rent or mortgage, and utilities
• Groceries (not restaurants)
• Insurance: health, car, home or renters
• Transportation to get to work or look for it
• Minimum payments on debts
• Childcare, if you'd still need it

Streaming services, gym memberships, dining out and extra debt payments can be cut in an emergency, so they don't count. For most households, essentials are 60–75% of normal spending. If you don't know your number, the family budget calculator gives a starting estimate by line.

Three months or six?

Aim toward six months or more if:

• You are the only earner in your household
• Your income is irregular, such as commission, freelance or seasonal work
• Your field takes a long time to hire, or layoffs in your industry tend to come in waves
• You own a home or older car that could need a large repair

Three months is often enough if your household has two stable incomes and each could cover the essentials alone for a while.

How long it takes to build

We ran a household with $4,200 in monthly essentials and $3,000 already saved through the emergency fund calculator, with the savings account earning 4% a year:

Interest helps a little. At $400 a month, the account earns about $2,300 on the way to six months. But the deposits do almost all the work. Doubling the deposit roughly halves the time.

A plan that works in stages

If the full amount feels out of reach, build it in steps:

1. Starter fund. Save $1,000 to $2,000 first. That covers the most common surprises, like a car repair or an insurance deductible.
2. Pay down high-interest debt. With the starter fund in place, put extra money toward credit cards. See why minimum payments take so long.
3. Build to three months, then six if your situation calls for it.

Automate it. Set a transfer to savings for the day after payday. Money that moves before you see it is much easier to save.

Where to keep it

The money needs to be safe and available within a day or two. Good choices are a high-yield savings account at an FDIC-insured bank or a money market fund. Rates on these have been around 4% in recent years, which keeps the fund from losing much to inflation. Avoid keeping it in stocks. A market drop tends to arrive at the same time as layoffs.

After you use it

Using the fund is the point. Afterward, restart your monthly deposit until the balance is back to target. Run your own numbers in the emergency fund calculator to see your target and the date you'll reach it.