UK Monthly Budget Calculator

How to use this budget calculator

Enter your real take-home income — the amount that arrives in your bank account after tax and National Insurance. Do not use your gross salary, as budgeting from the wrong number is one of the most common reasons budgets fail. If your income varies month to month, use the average of the last three months, rounding down slightly to be safe.

Work through each cost category using your actual recent spending, not what you think you should be spending. Pull up your last two or three bank statements and look at what you actually paid in each category. The food and eating-out figures are where most people underestimate — be honest with yourself here, as the calculator is only useful if the inputs are accurate.

What the results mean

If your left-over figure is positive, that money is available for savings, debt repayment or building an emergency fund. A savings rate of 10-20% is generally considered healthy, though anything above zero is a foundation to build on. If you are saving less than you would like, the breakdown by category helps identify where the largest opportunities are.

If the calculator shows a shortfall — your costs exceed your income — this is important information, not a cause for panic. It means adjustments are needed, either to spending, income, or both. The most impactful categories to review first are usually subscriptions, eating out and transport, where small changes produce the largest monthly savings.

Taking the next step with Ask Fin

This calculator gives you a snapshot. Ask Fin gives you the full picture — a dynamic monthly budget you can update, a Leak Detector that finds forgotten costs, a Savings Builder for your goals, and 11 more tools. All for £4.99/month, with no minimum term.