🛡️ Emergency Fund Calculator
Find out exactly how much you need in your emergency fund — and how long it will take to get there.
Find out exactly how much you need in your emergency fund — and how long it will take to get there.
How much should an emergency fund be?
Most financial planners recommend three to six months of essential expenses — enough to cover rent or mortgage, utilities, food and minimum debt payments through a job loss or unexpected event. If you are self-employed, have variable income, or have dependants, aim for six to twelve months. Hold it in a high-yield savings account, not invested in the market.
| Scenario | Recommended Fund | Months to Save |
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How to use this calculator
Takes about 2 minutes.
- Enter your monthly take-home income and essential monthly expenses
- Select your job security band (stable, average, variable, or self-employed)
- Add the number of dependants in your household
- Enter what's already saved in your emergency fund and how much you can save each month
- Click Calculate to see your target fund size and the months it will take to fully build it
Try these scenarios
Tap a scenario to load it into the calculator above.
Key concepts
The 3-6 month rule. Most personal-finance authorities — Vanguard, the FCA's MoneyHelper service, Investopedia — converge on holding 3-6 months of essential expenses (not income) in accessible cash. Single earners with dependents should aim higher; dual earners can sit at the lower end.
Expenses, not income. What matters is what you must pay each month if income stops — rent or mortgage, utilities, food, insurance, minimum debt payments. Discretionary spending pauses in a crisis, so don't size the fund against your current lifestyle.
Job-security weighting. Tenured, in-demand, or unionised roles warrant smaller funds (3 months). Contract, freelance, commission, or industry-shock exposure warrants 6-12 months. The 2008 financial crisis had the average US unemployment spell run 9 months.
Where to hold it. A high-yield savings account, money-market fund, or short-term Treasury bill ladder. The point is FDIC / FSCS protection and instant-to-five-day access — not return. Don't put emergency funds in stocks: downturns and job losses correlate.
How long to build it. If you can save 10-20% of net income, a 6-month fund typically takes 1-2 years to build from zero. Some prefer to build a starter $1k cushion fast, attack high-interest debt next, then top up to the full 3-6 months — Dave Ramsey's Baby Steps codify this order.
Worked example — UK couple, one earner on contract
A Bristol-based household has essential outgoings of £2,650 a month: £1,200 mortgage, £180 council tax, £220 utilities, £450 groceries, £160 fuel and transport, £290 insurance and subscriptions, and £150 minimum debt payments. Joint take-home is £4,800 a month — but only one of the two earners has a permanent contract; the other is a freelance designer with lumpy 3-6 month projects. They currently hold £4,000 in an easy-access account and can save £600 a month.
The target follows the FCA MoneyHelper guidance plus a job-security weighting: 6 months of essentials × £2,650 = £15,900. The gap to target is £15,900 − £4,000 = £11,900. At £600 a month, that takes about 20 months to close — call it just under two years. Holding the fund in an easy-access cash ISA paying 4.2% (typical for the top UK rates as of mid-2026) earns roughly £450-£600 of tax-free interest across the build period, slightly accelerating the finish line.
Flex one input. If the freelancer lands a contract that lifts the savings rate to £900 a month, the build finishes in about 14 months instead of 20. Conversely, if essentials creep to £2,950 — a fixed-rate mortgage rolling onto a higher product, for example — the target jumps to £17,700 and the timeline at the original £600 stretches to 23 months. The calculator above will swap any of these numbers in real time so you can see which lever moves the date most.
Common mistakes
- Sizing the fund against net income, not essential expenses. A household netting £4,800 but with £2,650 in true essentials should target 6 × £2,650, not 6 × £4,800. The difference is £12,900 versus £28,800 — the bigger figure is correct only if every penny of lifestyle is non-negotiable, which it almost never is when income stops.
- Holding it in the same current account as everyday spending. Behavioural data is consistent: money you see is money you spend. Hold the fund at a separate provider, ideally one without a linked debit card, so it takes 24-48 hours to move into spending money. The friction is the feature.
- Investing the fund "for better returns". A 30% equity drawdown the same week you're made redundant is exactly the scenario the fund exists to avoid. Cash earning 4% is the right vehicle here; the long-run return penalty is small and the worst-case protection is large.
- Never recalibrating the target. Essentials drift up over time: mortgage roll-offs, a new child, a change of school catchment. Most people size the fund once at 28 and never revisit it. Re-check the target every January and after any major life event (move, baby, marriage).
- Forgetting to refill after a draw. The fund's job is to absorb shocks — boiler breakdown, redundancy, family emergency. Once it's been used, set up a fresh standing order to rebuild it within 12-18 months. Funds that get drawn and never refilled silently disappear.
Frequently Asked Questions
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