Emergency Fund Calculator
An emergency fund is not an investment. Its job is to stop a surprise turning into a debt, and it is the highest-priority saving most people have.
How large it should be
The fund is sized against essential expenses, not total spending. In a genuine emergency you stop the subscriptions, the restaurants and the holidays. Including them inflates the target and delays reaching it.
Essential means: housing, utilities, food, transport to work, insurance premiums, minimum debt payments, childcare, and medication. Everything else is discretionary by definition.
How many months depends on how quickly your income could be replaced and how volatile it is:
| Situation | Months |
|---|---|
| Two stable salaried incomes, no dependants | 3 |
| Single stable income, or dependants | 6 |
| Commission or variable pay, specialised role | 9 |
| Self-employed, or sole income with dependants | 12 |
Where to keep it
The requirements are unusual and they rule out most things:
- Immediately accessible. An emergency that takes 30 days to access is not covered.
- Capital secure. It must be worth what it says. This rules out anything invested in markets — an emergency fund that falls 25 % in the same recession that costs you your job has failed at its only task.
- Separate from current account. Money you see daily gets spent.
- Protected. Within the deposit guarantee limit of your jurisdiction, at a covered institution.
An instant-access savings account meets all four. Do not chase yield here. The difference between a 3 % and a 4 % rate on a £10,000 fund is £100 a year — not worth any compromise on access or security.
A reasonable refinement once the fund is large: keep one month instantly accessible and the rest in a notice or short fixed-term account paying more, accepting a small delay on the bulk.
Where it sits in the order
The standard sequence, and the reasoning behind it:
- One month of essentials. This alone prevents most small surprises becoming credit card debt.
- Employer pension match. An immediate guaranteed return that nothing else matches.
- Clear high-interest debt above roughly 8 %. Paying off 22 % debt is a guaranteed 22 % return.
- Complete the emergency fund to your target months.
- Then invest for longer-term goals.
Steps one and three are deliberately interleaved. Building a full six-month fund while carrying credit card debt costs more in interest than the fund earns, but having no buffer means the next unexpected expense goes straight back on the card. One month first, then attack the debt.
Replace it after you use it. Using the fund is not a failure — it is the fund doing its job. Rebuilding it becomes the priority again afterwards.
Frequently asked questions
Should I build an emergency fund or pay off debt first?
Both, in sequence. Build roughly one month of essentials first so the next surprise does not go on the card, then attack high-interest debt, then complete the fund. Carrying 22 % debt while holding a large cash buffer earning 3 % costs you money every month.
Can I keep it invested?
Not the core of it. The fund's purpose is certainty, and markets can fall sharply at exactly the moment you need the money — job losses and market falls are correlated. Some people invest amounts above six months of cover, which is a reasonable compromise.
What counts as an emergency?
Job loss, urgent medical or dental costs, an essential home or car repair, or emergency travel. A holiday, a new phone and Christmas are not emergencies — they are predictable and should be budgeted for separately.
Is six months too much cash to hold?
It is a real trade-off: cash loses purchasing power to inflation. The counter-argument is that the fund's return is not its interest rate but the debt and forced selling it prevents. For most people that is worth far more than the yield forgone.