How Big Should Your Buffer Be?

The right buffer is measured in months of spending, not a round dollar figure — and the number of months depends on how steady your income is.

The familiar rule of thumb is three to six months of essential expenses held in cash. It is a good starting point, but treating it as one-size-fits-all misses the real question: how long could your income stop, and how hard would it be to replace?

Size it to your situation. A dual-income household where both partners are in stable, salaried jobs can sit comfortably at the lower end — perhaps three months — because the chance of both incomes stopping at once is low. A single-income household supporting dependants needs more, because everything rests on one job. If your income is variable — commission, freelance, or business — the cushion should be larger still, because lean months are a feature, not an emergency.

Note that the buffer covers essential spending, not your full lifestyle. In a real squeeze you would cut the discretionary wants first, so size the fund against rent, food, transport, insurance, and loan repayments — the bills that do not pause.

The point is not to hit a magic number but to buy yourself enough runway to handle a setback without panic. More uncertain income and more dependants both push the number up.

Illustrative example: months of buffer by situation

The chart shows a sensible starting range for different circumstances, from a stable dual-income household up to the self-employed. Use it as a guide, then adjust for your own job security and how quickly you could find new income. When in doubt, hold a little more than feels necessary.