Monthly Budget Calculator

To calculate a monthly budget, add up your monthly spending and subtract it from your monthly net income: money left over = net income − total monthly spending. Then work out savings rate = money left over ÷ net income × 100, which tells you what share of your pay you keep each month.

After that, look at each spending category as a percentage of income to see where the money actually goes, and group them into essentials and lifestyle so you can compare the split against the 50/30/20 rule. Use net (after-tax) pay, and convert annual bills to a monthly figure by dividing by twelve.

• Total spending = the sum of all eight categories you enter.
• Left over = net income − total spending. A negative figure means the shortfall is coming from savings or credit.
• Savings rate = leftover ÷ income, shown as a percentage.
• Essentials vs lifestyle groups housing, utilities, food, transport, debt and insurance as essentials, and subscriptions plus other spending as lifestyle.

The bar chart ranks categories from largest to smallest as a share of income, which is usually the fastest way to spot where a budget is out of balance.

Assumptions: every figure is a monthly amount in a single currency, income is after tax, and no inflation, interest or investment growth is applied. Changing currency changes formatting only — never the numbers.

The 50/30/20 rule is a quick sanity check on the shape of a budget: roughly 50% of net income on needs, 30% on wants and 20% on savings and extra debt repayment.

• Needs (target ≈ 50%) — the essentials total in your results: housing, utilities, groceries, transport, insurance and minimum debt payments.
• Wants (target ≈ 30%) — the lifestyle total: subscriptions and other discretionary spending.
• Savings (target ≈ 20%) — your leftover amount, shown as the savings rate.

Treat it as a direction of travel rather than a pass/fail test. If housing alone takes 40% of your pay, hitting 50% for all needs is unrealistic and the useful question becomes which lifestyle costs can flex instead.

• Left over — money not already committed this month. Positive is breathing room; negative means the gap is funded by savings or borrowing.
• Savings rate — the share of pay you keep. Useful because it stays comparable when your income changes.
• Biggest category — where the pressure is. Housing is often the largest line, and rules of thumb such as keeping it near 30–35% of net income are guidelines rather than fixed limits; what counts as workable depends on your income, location and other commitments.
• Essentials vs lifestyle — how much of your budget you can realistically change within a month.

Daniel brings home 4.000,00 €. His rent is 1.300,00 €, utilities 220,00 €, groceries 520,00 €, transport 300,00 €, debt payments 350,00 €, insurance 180,00 €, subscriptions 70,00 € and other spending 400,00 € — a total of 3.340,00 €.

That leaves 660,00 € a month, a savings rate of 16.5%. Housing takes 32.5% of his pay, which is within the commonly quoted 30–35% comfort zone, while his 470,00 € of subscriptions and other spending is the easiest place to find another 150,00 € and push his savings rate past 20%.

Against the 50/30/20 rule his needs are 2.870,00 € (71.8%), wants 470,00 € (11.8%) and savings 16.5% — needs-heavy rather than lifestyle-heavy, so the realistic lever is a cheaper transport or insurance arrangement, not cancelling streaming services.

Amounts follow the currency selected in the calculator above. AffordPilot never converts between currencies — the figures are the same either way.

Once you know your leftover amount, the useful follow-up questions are about specific decisions:

• Thinking about a one-off purchase? The Can I Afford It calculator checks it against your savings and emergency buffer.
• Now that you know what your essentials cost each month, the emergency fund calculator turns that essentials total into the reserve needed to cover them if your income stopped.
• Rent is usually the largest line in the budget. The rent affordability calculator shows what your income leaves for rent once essentials, debts, utilities and a buffer you choose are taken out.
• Considering a car? The car affordability calculator turns your leftover income into a realistic car price, including insurance, fuel and maintenance.
• Or browse all AffordPilot calculators, including the money calculators category.