Budget Calculator
Compare monthly income with living costs, debt payments and savings allocations without imposing a spending rule.
Unallocated income (negative = deficit)
No mandatory 50/30/20 rule or affordability recommendation. Use income actually available after deductions if that is your planning basis. Annual bills need conversion to monthly equivalents. Percentage shares are undefined at zero income.
Formula checked · NumberSwift · Review process
For informational purposes only. Results are estimates and do not constitute financial advice.
How this calculator works
Enter income and outgoings on the same monthly basis. Living and debt expenses are totalled separately from savings because a savings transfer is an allocation rather than consumption. Subtract both from income to find the amount not yet assigned. A negative result indicates planned allocations exceed entered income. Category percentages use income as their denominator, so they need not sum to 100% when some income remains unallocated.
Formula
Expenses = housing + food + transport + debt + other. Total allocations = expenses + savings. Unallocated income = income − allocations. Category share (%) = category amount ÷ income × 100.
Assumptions & limitations
No mandatory 50/30/20 rule or affordability recommendation. Use income actually available after deductions if that is your planning basis. Annual bills need conversion to monthly equivalents. Percentage shares are undefined at zero income.
Worked example
Income of 4,000 with 1,200 housing, 400 food, 300 transport, 200 debt, 300 other expenses and 500 savings gives 2,400 expenses, 2,900 total allocations and 1,100 unallocated. Housing is 30% of income and savings is 12.5%.
Our approach to calculations ↗Common questions
Why are savings shown separately from expenses?
Savings move money to a future-use allocation instead of consuming it. Both reduce currently unallocated income, so the combined total is also shown.
Does a negative remaining amount mean I should cut a particular category?
It identifies a numerical gap only. The tool does not choose spending priorities or provide personalized financial advice.
Why do the percentages not always total 100%?
They describe entered amounts as shares of income. Unallocated income, or a deficit, accounts for the difference.