What this calculator works out
Your survival budget is the smallest amount of money you need each month to keep going. Housing, council tax, energy, food, getting to work, insurance you cannot drop, care costs and the minimum payments on any debts. Nothing else. No streaming, no eating out, no holidays, no new clothes. It is not how you want to live — it is the floor you would drop to if things got tight.
Three other figures come from it: how big your emergency fund needs to be, what you would need to cover if your income stopped, and how much headroom you have each month once the essentials are paid.
The method, in full
- Add up the ten essential categories. That total is your survival number.
- Multiply it by twelve for the annual figure.
- Take the survival number off your monthly take-home pay. What is left is your headroom.
- Divide the cash you could reach today by the survival number. That is how many months you could survive if your income stopped tomorrow.
- Multiply the survival number by three and by six for the two common buffer targets.
Why it is your survival spending, not your full spending
Emergency fund guidance usually says three to six months of expenses. In an emergency you would cut back to essentials, so the essentials are what the buffer needs to cover, which gives a smaller target.
The assumptions
- Everything is monthly. If a bill is annual — car insurance, a TV licence — divide it by twelve before you enter it.
- Debt means minimums only. Put in the contractual minimum payment, not what you are currently overpaying.
- No inflation, no interest, no growth. This is a snapshot of the current month.
- Rounding. The result is your figures added together. Where a figure is shown to the nearest pound it is only the display that is rounded — the arithmetic runs on what you typed.
- Your figures stay in your browser. There is no server call. Close the tab and they are gone, so print or copy the result if you want to keep it.
Entering accurate figures
Use what your bank statements show, not what you think you spend; three months of statements give a reliable figure. If you would rather work through it in a structured tool first, the MoneyHelper budget planner is free and government-backed.
Include only what you could not stop. A gym membership or a handset upgrade is not essential; a basic phone contract may be.
What to do with the answer
Write it down somewhere you will find it. Use it to size your emergency fund with the emergency fund calculator, and to see how your headroom affects debt repayments with the debt payoff calculator.
To work through yours with someone, the free Financial Freedom Score takes about seven minutes, and the £39 Financial Health Check (free for Buzz Accounting clients) goes through it with a coach.