Direct answer
A useful emergency-fund target starts with the expenses that would continue during an interruption, then accounts for reliable income and the time your household might need to recover. A range is usually more honest than one universal number.
Begin with continuing monthly expenses
List the costs that would continue during a job loss, medical event, major repair, or other disruption. Common examples include housing, utilities, groceries, insurance, transportation, minimum debt payments, health costs, and essential dependent care.
Separate essential continuing expenses from spending that could be paused. This produces a more useful planning base than multiplying total current spending without reviewing it.
Subtract income you can reasonably rely on
Some households would retain part of their income during a disruption. Include only amounts that are reasonably dependable, and avoid assuming that uncertain bonuses, overtime, investment gains, or informal help will always be available. The difference between continuing expenses and reliable continuing income is the monthly shortfall the fund needs to cover.
A worked example
Suppose essential expenses would total $4,200 per month and reliable continuing income would be $1,200. The monthly shortfall is $3,000. Three months of that shortfall is $9,000, six months is $18,000, and nine months is $27,000.
Those figures are planning points, not a requirement. A household can start with a smaller first milestone, build it consistently, and reassess after changes in employment, housing, insurance, debt, or dependents.
When a longer range may be useful
A longer coverage period may deserve consideration when income depends heavily on one earner, work is seasonal or volatile, replacement employment could take longer, health or dependent-care needs are significant, or insurance deductibles and major repair exposure are high. Multiple stable income sources and strong backup resources may support a shorter range.
Keep emergency savings secure and accessible enough for its purpose. The CFPB describes an emergency fund as a cash reserve for unplanned expenses or financial emergencies and recommends rebuilding it after it is used.
Sources and next step
Use the linked Rich Direction calculator to test your own assumptions. Results are general educational estimates, not individualized financial, lending, tax, legal, or investment advice.