Emergency Fund Calculator

Calculate the right size for your emergency fund based on your essential monthly outgoings. See how long it will take to build from your current savings rate.

Last updated: April 2026

Your monthly outgoings
Your emergency fund
Target fund size
-
-
Monthly essentials -
To save monthly (12 months) -
To save monthly (24 months) -

How much should your emergency fund be?

The standard UK financial advice is to hold three to six months of essential outgoings in an accessible savings account. Essential outgoings are the costs you must cover regardless of circumstances: housing, utilities, food, transport, and minimum debt payments. Discretionary spending such as subscriptions, eating out, and entertainment is excluded because you would cut these immediately if your income stopped.

Who needs more than six months?

Self-employed people, freelancers, and those on variable or commission-based income are generally advised to hold nine to twelve months of cover, because their income is less predictable and a period of low income can occur without warning. Similarly, anyone in a niche industry, approaching redundancy, or with dependants who could not quickly find alternative income should consider holding more.

Where to keep your emergency fund

An emergency fund should be kept in an instant-access savings account, not invested. The purpose of the fund is certainty, not growth. It needs to be accessible on the same day or next working day without penalty. Many people keep it in a separate account from their current account to reduce the temptation to spend it, but close enough that they can access it quickly if needed. A cash ISA can work well for the tax-free interest, provided the account allows withdrawals without restrictions.

Frequently asked questions

A Cash ISA is a good home for an emergency fund if the account allows instant access without notice periods. Some fixed-rate cash ISAs lock your money for a term - these are not suitable for emergency savings. Flexible cash ISAs that allow withdrawals and re-deposits within the same tax year are ideal. The interest will be tax-free, which is a modest bonus on top of the security the fund provides.
Essential outgoings are costs you cannot avoid: rent or mortgage, council tax, utility bills, minimum debt payments, food, and transport to work. They do not include subscriptions, gym memberships, dining out, or discretionary spending. When calculating your emergency fund target, use the minimum you genuinely need to maintain your life and obligations, not your average monthly spend.
Generally, build a small emergency fund (one month of expenses) before aggressively paying down debt. Without any buffer, an unexpected expense could force you back into more expensive debt. Once you have a basic buffer, focus on clearing high-interest debt (credit cards, overdrafts) before building the full emergency fund, as the interest saved outweighs the modest interest earned on savings.