The emergency reserve is measured in months of expenses, not dollars. The right size depends on how quickly the household could replace its income if the primary stream disappeared. Three months is the floor for a dual-income household with stable employment; six is the working target; twelve is warranted in specific cases.
- 01Compute the correct reserve size for a specific household.
- 02Distinguish reserve from short-term named savings.
- 03Explain when the reserve should be larger than six months.
The formula
Reserve equals fully-loaded monthly expenses times months. Fully-loaded means the number you actually spend, including irregular items amortized monthly — car maintenance, insurance premiums, gifts. Do not use a discretionary-stripped 'if the world ends' number; the reserve exists precisely because the world does not end cleanly.
The dial
Three months for a dual-income household with two stable roles in different industries. Six months for the standard case. Nine to twelve months for a single-income household, a household with a variable-income earner, or a household with a business owner. The dial moves with the fragility of the income.
The trap
Overfunding the reserve is a real cost. Every dollar sitting in savings above the reserve target is a dollar not compounding at the household's investment rate. Beyond the reserve, the money belongs in an investment account or a Treasury ladder — not in savings.
- Fully-loaded monthly expenses times the correct number of months.
- Dial moves with income fragility, not general anxiety.
- Overfunding is a real cost; move the excess out.