How to use this budget planner
The page starts with an example budget so you can see the shape of the thing. Overwrite it with your own numbers — click any field and type. Add rows for anything missing, delete what does not apply, and everything recalculates as you go.
Use take-home pay, not gross salary. Budgeting from a pre-tax figure is the most common reason a budget looks fine on paper and fails in practice.
Getting the numbers right
Two habits make the difference between a budget that works and one that quietly falls apart.
Use real figures, not intended ones. Open your bank statement from last month and copy the actual totals. Almost everyone underestimates food, transport and small discretionary spending by 20–40%. A budget built on what you meant to spend is fiction, and it will fail in week two.
Convert annual costs to monthly. Car insurance, road tax, professional subscriptions, the annual software renewal, Christmas, birthdays, holidays. Add them up for the year, divide by twelve, and enter that as a monthly line. These "surprise" expenses are not surprises — they happen every year, and treating them as such is what stops them landing on a credit card.
The three categories
Needs are the things you cannot stop paying without your life materially changing: housing, utilities, basic groceries, transport to work, insurance, minimum debt payments. Be honest here — a phone contract is a need, the flagship handset on a 36-month plan is closer to a want.
Wants are everything that makes life enjoyable but could be paused: eating out, streaming services, hobbies, clothes beyond replacement, travel, the nicer version of something you needed anyway.
Savings and debt repayment covers your emergency fund, pension and investment contributions, and any payment above the minimum on a debt. Overpaying debt belongs here rather than in needs, because it builds your net worth exactly as saving does.
What the 50/30/20 rule is actually for
Half of take-home pay to needs, 30% to wants, 20% to savings and debt repayment. It comes from Elizabeth Warren's book All Your Worth, and its value is not precision — it is that it gives you a shape to compare against in ten seconds instead of a spreadsheet you will never open twice.
The signal to watch is the needs percentage. Below 50% you have real slack. Between 50% and 60% you are fine but should not take on more fixed commitments. Above 60%, ordinary events — a boiler failure, a fortnight of reduced hours — turn into borrowing, because there is nothing to absorb them.
The rule is also honestly unrealistic for a great many people. In expensive cities, rent alone can be 40–50% of take-home pay for someone on a median income. If your needs are at 70%, the answer is not to feel bad about a benchmark; it is to recognise that the fixable line is almost always housing or transport, and that no amount of trimming small discretionary spending will close a gap of that size.
Reading the savings rate
The savings rate combines your explicit savings lines with anything left unallocated. It is the single most predictive number in personal finance: it determines how long you must work before you could stop. At a 10% savings rate, a working life is roughly forty years. At 25% it is closer to twenty-five. At 50% it is around seventeen.
If yours is under 10%, look at the wants column first. It is nearly always more elastic than needs, and cutting there requires no upheaval — just decisions.
What happens to your data
Nothing is saved. There is no account, no cloud sync, no server, and no local storage — which means there is nothing to leak, and equally that closing this tab erases everything you typed. That is a deliberate trade for a page where you are entering your salary and your rent.
Use the CSV export if you want to keep a copy. It opens in Excel, Google Sheets or Numbers, and keeping one file per month is enough to spot trends that a single month never shows — the subscription that crept up, the season when the energy bill doubles, the month you always overspend.
Not financial advice. This calculator is an educational tool that models a simplified scenario. Real outcomes depend on fees, taxes, inflation and market behaviour that no calculator can predict. Speak to a regulated adviser before making a financial decision.