An emergency fund is three to six months of essential outgoings, MoneyHelper's rule of thumb, kept in instant-access savings. Enter your essentials, pick the months of cover, add what you have saved and what you can add each month, and the calculator gives you the target and the date.
Rent or mortgage, council tax, energy, water, broadband, food, transport to work, insurance, minimum debt payments, childcare. Not the full month's spending. The fund is there to keep the lights on if income stops, not to keep every subscription running.
Three months or six?
Three months: a steady job, two incomes in the household, or a strong support network.
Six months: self-employed, single income, a specialised job that takes time to replace, or dependants.
Somewhere between, most people. Start with three; extend it once it is there.
Where to keep it
Instant-access savings, separate from your current account so it is not spent by accident. Not investments, which can be down exactly when you need the money. Basic-rate taxpayers can earn £1,000 of interest a year tax-free under the Personal Savings Allowance, and a cash ISA shelters interest beyond that.
Find your essentials figure without guessing
Import last month's bank CSV into The Income Tracker and add up the Housing, Bills, Groceries, Transport and Health categories. That is your essentials number, and it updates every month.
The Income TrackerTrack it free. No account, no bank login.
MoneyHelper suggests three to six months of essential outgoings. Use three if your income is steady and six if it is not or you have dependants.
Should my emergency fund be in an ISA?
It should be instant access. A cash ISA can be, and it shelters interest above your Personal Savings Allowance. Avoid fixed-term accounts and investments for this money.
How many people in the UK have no savings?
The FCA's 2024 Financial Lives survey found 10% of adults had no cash savings and a further 21% had under £1,000.
Is the calculator free?
Yes, and nothing you enter is stored or sent anywhere.
Sources and checking
Facts on this page were last checked on 2026-09-08 against: