Should I use fixed costs or total spending?

Fixed costs. Discretionary spending drops on its own in a real emergency, and including it produces a target so large that most people abandon the goal entirely.

How many months of cover do I need?

Three to six is the usual range. Irregular income, a specialised role, home ownership, or being the sole earner all push you toward the larger end.

Should I pay off debt or build this first?

Usually build one month of fixed costs first, then clear high-interest debt, then continue. Without any buffer you re-borrow at the first surprise, which defeats the payoff.

Free tool · Savings

Emergency fund calculator

Monthly fixed costs and months of cover → target, shortfall, and how long to get there.

Runs in your browser · no account required · amounts use any currency unit

Monthly fixed costs

Rent, utilities, food, insurance, minimum debt payments — not total spending

Months of cover

Usually 3–6

Already saved

Monthly contribution

Results

Target6,000

Months you already cover0.5

Still to save5,000

Time to target1 year 5 months

In short

What is this?

An emergency fund should be sized from your monthly fixed costs — rent, utilities, food, insurance, minimum debt payments — rather than your total spending. Discretionary spending drops on its own in a real emergency, and budgeting six months of your comfortable lifestyle produces a target most people abandon.

Use fixed costs, not total spending

This is the input that matters and the one people get wrong. Enter what you must pay: housing, utilities, groceries, insurance, transport to work, and minimum debt payments.

Leave out dining out, subscriptions you would cancel, and discretionary shopping. In a genuine emergency those drop on their own, and including them inflates the target to a point where people give up before starting.

How many months to choose

Three to six months is the usual range. Push toward the larger end with irregular income, a specialised role where finding work takes months, sole responsibility for a household, home or vehicle ownership, or limited access to affordable credit.

Sit at the smaller end with stable salaried employment in a field with steady demand, a second earner, or genuine family support you could rely on.

Build it in stages

A six-month target is paralysing from zero. One month of fixed costs alone eliminates the most common reason people take on high-interest debt — a mid-sized surprise in a bad week. Reach that first, then continue.

There is a real argument for pausing after the first month to clear high-rate debt before building further, since carrying a punitive balance while accumulating low-yield cash is a losing trade.

Keep it separate from sinking funds

Annual insurance, car servicing, and December are not emergencies — they are appointments. Funding them from the emergency fund keeps it permanently depleted and makes surprises feel constant when they are not.

FAQ

Should I use fixed costs or total spending?: Fixed costs. Discretionary spending drops on its own in a real emergency, and including it produces a target so large that most people abandon the goal entirely.
How many months of cover do I need?: Three to six is the usual range. Irregular income, a specialised role, home ownership, or being the sole earner all push you toward the larger end.
Should I pay off debt or build this first?: Usually build one month of fixed costs first, then clear high-interest debt, then continue. Without any buffer you re-borrow at the first surprise, which defeats the payoff.

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