A useful emergency fund starts with essential monthly expenses: housing, food, utilities, insurance, transportation and minimum debt payments. Discretionary spending can be excluded or reduced when estimating a bare-bones number.
Three months versus six months
Three months of essential expenses may be reasonable for a household with stable income, low debt and multiple earners. Six months or more may be better for variable income, a single-earner household, self-employment, health concerns or a specialized job market.
Liquidity matters
Emergency savings should be accessible. A high-yield savings account, money market account or other cash-like option is usually easier to use than selling investments during a bad market. The goal is reliability, not maximum return.
Build it in stages
If the full target feels large, start with a smaller milestone such as one month of expenses or a fixed amount that covers common problems. Progress matters because even a partial fund can reduce the need for high-interest debt.