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Emergency fund

How Big Should My Emergency Fund Be on $6,000 a Month?

The rule of thumb is “three to six months”. On $6,000 of monthly expenses that is a $18,000 spread — which is a lot of money to leave to a rule of thumb.

The short answer

Three months is $18,000, six is $36,000, nine is $54,000. Which one you need is set by how replaceable your income is, not by the rule. Building the $36,000 at $800 a month takes 45 months in a checking account and 42 months at 4% — the account earns you three months of the work.

What each target costs

TargetMonths of expensesBalanceMonths to build at $800/mo
Thin3$18,00023
Standard6$36,00042
Conservative9$54,00060

Build times assume a 4% annual rate compounded monthly on the balance as it grows. At 0% the same three targets take 23, 45 and 68 months.

Which number is actually yours

Your situationTarget
Two incomes, in-demand skills, no dependants3 months
One income, or a specialised role with a long search6 months
Self-employed, commission-based, or a single income with dependants9 months
A known large expense inside 12 months6 months plus that expense

The variable is how many months of searching stand between you and the next paycheck. Someone with a 3-week replacement time and someone with a 7-month one do not need the same number.

Where it sits matters more than people think

AccountRate assumedInterest on $36,000 in one year
Checking0%$0
High-yield savings4%$1,467
Money market4%$1,467

The rate is an assumption, not a quote — check what is actually on offer. The point is the shape: the same money, doing the same job, differs by roughly $1,500 a year depending only on which account it sits in. An emergency fund must stay liquid and principal-stable, which rules out anything that can be down 20% on the day you need it.

What this assumes

  • $6,000 a month of essential expenses — housing, food, insurance, minimum debt payments, transport. Not your current total spending.
  • $800 a month available to save toward the fund.
  • A 4% annual rate on savings, compounded monthly.
  • No withdrawals during the build.

Every one of these is an input, not a fact about your situation. Change them in the calculators below and the answer changes with them.

Run the math yourself

These calculators give you the same numbers we used above — with your own inputs.

Cash Flow CalculatorFind the real monthly essential-expense number.Goal Planning CalculatorTime to reach $18K, $36K or $54K at your savings rate.Compound Interest CalculatorWhat the fund earns while it sits there.

Bottom line

Work out your essential monthly expenses first — most people guess high, because they count their whole budget rather than the part that would survive a job loss. Multiply by the number of months your income would realistically take to replace. Keep it somewhere liquid and boring. Then stop adding to it and send the $800 somewhere it can grow.

Disclaimer. This is educational, not personalized financial advice. Numbers depend on your specific tax bracket, state, and goals. Verify with the IRS, SSA, or a CPA before acting. See our Financial Disclaimer.

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