Practical money guide

How much emergency fund do I need?

Start with essential monthly spending and a coverage period you choose. Then check how much cash remains after a one-off shock. Treat replacement income as a separate coverage assumption.

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1. Start with expenses you would still have

List housing, food, utilities, minimum debt payments, and other commitments that continue when income stops. Use recent bills rather than an unusually cheap month. Divide predictable annual expenses by twelve. Keep planned purchases separate so the reserve is not already promised to something else.

2. Separate a shock from the months after it

Our example starts with $18,000 and a $3,000 repair, leaving $15,000. Essential spending is $2,500 a month. A six-month target therefore needs $15,000 after the repair. This model deliberately bases the target on full essential spending, even when temporary income might reduce withdrawals.

3. Test the reliability of replacement income

With $500 of dependable monthly income, withdrawals fall to $2,000 and the remaining cash covers 7.5 months. Without that income, it covers six. Change the income input to zero and compare the result. The CFPB explains that an appropriate reserve depends on your circumstances; six months here is an example assumption, not a universal prescription.

4. Choose the next useful action

A negative reserve margin shows the shortfall against your chosen target. You can increase cash, reduce essential spending, or revisit the coverage period. If the buffer is too large to build immediately, use a smaller interim target and review it as circumstances change. Keep access to the reserve and repayment obligations in the decision.

Live model

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Assumptions

template: emergency_fund

cash_reserve = 18000 in usd
essential_spending_monthly = 2500 in usd
income_replacement_monthly = 500 in usd
shock_cost = 3000 in usd
target_buffer_months = 6

Inputs

What the model needs

Cash reserve: Liquid money that is genuinely available for an emergency.
Essential spending: Housing, food, utilities, insurance, and unavoidable minimums.
Replacement income: Reliable monthly income that would continue during the disruption.
Shock cost: An immediate repair, medical bill, deductible, or similar expense.
Target months: The buffer you want the post-shock reserve to cover.

Method

Formulas stay visible

post_shock_reserve = cash_reserve - shock_costmonthly_drawdown = essential_spending - replacement_incomecoverage_months = post_shock_reserve / monthly_drawdowntarget_reserve = target_months × essential_spendingreserve_margin = post_shock_reserve - target_reserve

The inputs and source use the same model. Open it in Continuum for a document you can keep and revisit.

Worked example

A six-month target after a repair

$18,000 reserve
$3,000 immediate shock
$2,500 essential spending
$500 replacement income

Result$15,000 remains and covers 7.5 months of a $2,000 monthly drawdown.

The $15,000 post-shock reserve meets the conservative six-month target based on essential spending alone. Replacement income extends coverage but does not reduce this target.

Stress-test it

Remove replacement income to test the more conservative case.
Increase the shock cost to the largest plausible deductible or repair.
Use essential spending, not an optimistic month with deferred bills.

Use it when

Setting a first emergency-fund target
Checking resilience before changing jobs
Testing whether a large purchase would leave enough cash

Know the boundary

The model does not estimate investment liquidity, taxes, or benefit eligibility.
Treat uncertain replacement income as zero or test both cases.
This is planning information, not individualized financial advice.

Questions

Is the target reduced by replacement income?

No. This model uses essential spending times target months for a conservative reserve target. Replacement income affects coverage months, so you can see both measures separately.

Why does the repair come out first?

It tests two events together: an immediate expense and the recurring withdrawals that follow. Set the shock to zero to examine income loss alone.

Should I use gross or take-home amounts?

Use actual spending and income available to pay it. Do not mix gross salary with take-home replacement income. The calculator does not determine tax or benefit eligibility.

Keep the reasoning

Turn this example into
your living model.

The full template opens as a local Continuum document. Edit every assumption, explore the result breakdown, and keep the source.

Open how much emergency fund do i need?