Emergency Fund Calculator
Work out how big your emergency fund should be from your essential monthly expenses, how far short you are, and how long it takes to build, or how much to save each month to have it by a date.
How to Use
- Enter what you must pay each month even in a bad month: housing, utilities, groceries, transport, insurance and minimum debt payments. Leave out spending you could stop.
- Choose how many months of those expenses to cover. Three to six is a common guideline; more if your income is irregular.
- Enter what you already have set aside and the APY of the savings account it sits in.
- Pick Time to build and enter what you can save each month, or Saving by a date and enter the number of months.
- Read the target, the shortfall and the time or monthly saving it takes, and follow the build-up on the chart.
Worked Example
A single renter’s first fund. Rent $1,200, utilities and phone $150, groceries $350, transport $250, insurance $120, minimum debt payments $150 and $100 of other essentials add up to $2,320 a month. Three months of cover is $2,320 × 3 = $6,960. With $2,000 already saved, the shortfall is $4,960 and today’s savings cover 0.8 months.
How long it takes. Saving $300 a month in an account paying 4% APY (0.3274% a month), the fund passes $6,960 after 15.8 months, so in month 16: 1 year 4 months. Interest adds $227 on the way. Without interest it would take $4,960 ÷ $300 = 16.5, so 17 months.
The common mistake: sizing the fund from income. Three months of a $4,200 take-home pay is $12,600, almost twice the $6,960 this renter actually needs, and a target that big can feel out of reach. In an emergency you stop eating out and pause saving, so base the fund on the essential bills you would still have to pay. The Budget Calculator helps split needs from wants.
Show Work
Formulas
Why Months of Expenses
The Consumer Financial Protection Bureau describes an emergency fund as cash set aside for unplanned expenses or financial emergencies, such as car repairs, home repairs, medical bills or a loss of income, and says the amount you need depends on your situation. Measuring it in months of essential expenses ties it to the biggest of those risks, losing your income, because the question then is how long you could keep paying the bills while you find new work.
That is also why the common guideline is a range rather than one number. Three months is often suggested for a steady job in a two-income household, and six or more for a single earner, someone self-employed or anyone in work that is slow to replace. The CFPB suggests thinking about the unexpected costs you have actually had to set a first goal, and notes that if you live paycheck to paycheck or your pay varies, putting any money aside helps.
Being able to absorb a surprise bill is one of the things the Federal Reserve tracks in its Survey of Household Economics and Decisionmaking, which it has run every year since 2013 to measure the financial well-being of US households. Money for emergencies should be safe and easy to reach: deposits at FDIC-insured banks are covered up to $250,000 per depositor, per bank, for each ownership category.
About This Tool
This calculator adds up your essential monthly expenses, multiplies them by the months of cover you choose, and compares the target with what you have saved. It then works out either how many months your regular saving takes to close the gap, or the monthly saving that closes it by a date, with interest at your account’s APY compounding monthly and deposits at the end of each month. The ruler shows how many months you are covered for today against the common three-to-six-month range, and the chart shows the fund growing to its target.
Everything runs in your browser; nothing you enter is sent anywhere. Estimates for planning and education — not financial, tax or legal advice.
Related tools: Savings Calculator, Budget Calculator, and Net Worth Calculator.
Frequently Asked Questions
How big should an emergency fund be?
A common guideline is three to six months of essential expenses; the Consumer Financial Protection Bureau says the right amount depends on your situation and the unexpected costs you have faced before. For essentials of $2,320 a month, three months is $6,960 and six months is $13,920. People with irregular income, one earner in the household or a job that would be slow to replace often aim higher.
What counts as an essential expense?
The bills you would still have to pay if your income stopped: rent or mortgage, utilities and phone, groceries, getting to work, insurance and health costs, and minimum debt payments. Leave out eating out, subscriptions and extra savings, which you would cut. A family of four with $2,100 of housing, $1,000 of groceries and $1,800 of other essentials needs $4,900 a month, so $29,400 for six months.
How long does it take to build an emergency fund?
Divide the shortfall by what you can save, allowing for interest. The family above has $8,000 and needs $29,400. Saving $600 a month in a 4% APY account gets there in 2 years 9 months; in an account paying nothing it takes 3 years, and saving $800 a month cuts it to 2 years 1 month. A three-month target of $14,700 takes 11 months at $600.
How much should I save each month to have it in two years?
Choose Saving by a date. A couple with $3,800 of essentials wants six months, $22,800, and has $5,000. To get there in 24 months they need to save $697.76 a month at 4% APY, or $741.67 a month if the account pays no interest. The calculator adds deposits at the end of each month and compounds the interest monthly.
Where should I keep an emergency fund?
Somewhere safe that you can reach within a day or two, such as a savings or money market account at an insured bank. The FDIC insures deposits up to $250,000 per depositor, per insured bank, for each ownership category. Shopping for a higher APY helps a little: at 4%, the family’s fund earns $1,984 of interest on the way to its $29,400 target.
How do I use the Emergency Fund Calculator?
Just type your numbers. The answer shows up right away — there is no button to press. Change anything and it updates by itself.
Does it cost anything or need an account?
No. The tool is completely free, there is no account to create, and it keeps working offline after the page first loads.
Is anything I type uploaded?
No. The tool works entirely on your device, so the values you enter never leave your browser.
Common Use Cases
A first safety net
A single renter with $2,320 of monthly essentials and $2,000 saved reaches a three-month $6,960 fund in 1 year 4 months at $300 a month.
A family fund
Six months of a family’s $4,900 essentials is $29,400; from $8,000, $600 a month at 4% APY gets there in 2 years 9 months.
Irregular income
A freelancer covering nine months of $3,300 needs $29,700; with $12,000 saved and $1,000 a month it takes 1 year 5 months.
Saving to a deadline
To reach $22,800 from $5,000 in two years at 4% APY, save $697.76 a month.
Checking you have enough
$18,000 against $2,500 of monthly essentials covers 7.2 months, $3,000 more than a six-month target.
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