How to calculate budget
Income = take-home pay + other after-tax income Expenses = housing + utilities + transportation + debt + groceries + dining + healthcare + children + miscellaneous Money left = income − expenses − planned savings Savings rate = planned savings ÷ income × 100 Annual surplus / shortfall = monthly money left × 12
Worked example. Monthly money left: $750.00.
Example inputs — Amounts entered: Per month; Take-home pay: $5,000; Other income (after tax): $0.00; Rent or mortgage: $1,500; Utilities, insurance & upkeep: $250; Car payments, fuel & travel: $400; Credit cards, student & other loans: $200; Groceries & household supplies: $400; Dining out & clothing: $150; Insurance & medical spending: $150; Childcare, tuition & support: $0.00; Savings & investments: $1,000; Pets, hobbies, gifts & vacations: $200. Starting values are illustrative.
Unallocated after expenses and planned savings.
From George Guju, founder of Calculyn · Educational calculator guidance, not professional advice.
How it works
A personal budget compares take-home income with planned expenses and savings. Housing, transportation, debt, living expenses, healthcare, children and miscellaneous costs are added separately, so you can see where your money goes. Savings are a planned allocation, not a living expense. Annual entries are divided by 12 to show the same monthly view.
Using the budget estimate
A useful personal budget starts with money that actually reaches your household, then gives that money a job. This planner uses broad spending categories rather than dozens of line items. Enter take-home pay and other after-tax income, then group recurring expenses into the categories below. The monthly remainder shows whether the plan leaves room for unexpected costs or spends more than the income entered.
Step-by-step inputs
- Amounts entered. Replace the starting value with your own, keeping the displayed unit and period. Starting example: Per month .
- Take-home pay. Replace the starting value with your own, keeping the displayed unit and period. Starting example: $5,000 .
- Other income (after tax). Replace the starting value with your own, keeping the displayed unit and period. Starting example: $0.00 .
- Rent or mortgage. Replace the starting value with your own, keeping the displayed unit and period. Starting example: $1,500 .
- Utilities, insurance & upkeep. Replace the starting value with your own, keeping the displayed unit and period. Starting example: $250 .
- Car payments, fuel & travel. Replace the starting value with your own, keeping the displayed unit and period. Starting example: $400 .
- Credit cards, student & other loans. Replace the starting value with your own, keeping the displayed unit and period. Starting example: $200 .
- Groceries & household supplies. Replace the starting value with your own, keeping the displayed unit and period. Starting example: $400 .
- Dining out & clothing. Replace the starting value with your own, keeping the displayed unit and period. Starting example: $150 .
- Insurance & medical spending. Replace the starting value with your own, keeping the displayed unit and period. Starting example: $150 .
- Childcare, tuition & support. Replace the starting value with your own, keeping the displayed unit and period. Starting example: $0.00 .
- Savings & investments. Replace the starting value with your own, keeping the displayed unit and period. Starting example: $1,000 .
- Pets, hobbies, gifts & vacations. Replace the starting value with your own, keeping the displayed unit and period. Starting example: $200 .
Worked example with the starting values
Using the starting inputs, the estimate is Monthly money left: $750.00 .
Unallocated after expenses and planned savings.
- Monthly take-home income
- $5,000.00
- Total living expenses & debt
- $3,250.00
- Planned savings & investments
- $1,000.00
- Savings rate
- 20%
- Income allocated
- 85%
Make a useful comparison
Use bank statements and recent bills to replace guesses. If an expense varies, choose a representative amount and keep a separate allowance for unusually expensive months. A budget can look balanced simply because an irregular expense was forgotten.
Choose monthly or yearly amounts before entering the categories and keep every field on that basis. Annual amounts are converted to monthly equivalents for the result. Mixing yearly insurance with monthly income without changing the entry basis creates a misleading shortfall.
Savings and investments are planned allocations rather than consumption. The results separate them from living expenses and debt, making it easier to see whether a negative remainder comes from essential costs, discretionary spending or an ambitious savings target.
Common mistakes to avoid
- Do not subtract payroll deductions again if the income field is already your take-home pay. For example, a workplace retirement contribution removed before the deposit should not also be counted as a new expense unless you intend an additional contribution.
- Avoid counting a credit-card purchase once in a living-expense category and again as the full card payment. Decide whether you are tracking current purchases or paying down older debt, then use a consistent method.
- A positive average monthly remainder does not guarantee enough cash on every bill date. Annual renewals and uneven income still need a cash buffer. Revisit the plan after a move, job change or change in household responsibilities.
Assumptions & limitations
- All entries use the same selected monthly or yearly period.
- Income is after tax; no tax rates are estimated.
- Costs are steady averages, not a bill-by-bill cash-flow forecast.
- Avoid counting costs or payroll savings twice. Unused categories can be zero.
- Example amounts are illustrative, not recommended spending limits.
Formula and assumptions reviewed October 2026 by the Calculyn team. How we build our calculators
Frequently asked questions
Should I enter gross income or take-home pay?
Use income after taxes and payroll deductions. Only include savings contributions made from that take-home income; do not count retirement contributions already withheld from your paycheck again.
Can I budget annually instead of monthly?
Yes. Select per year and enter annual amounts for every category. Results are converted to monthly averages. For monthly budgeting, divide irregular annual bills by 12 before adding them.
Where do insurance and loan payments go?
Include home insurance and property tax under housing and utilities unless already in your mortgage payment. Car payments and auto insurance belong under transportation. Put credit card balance repayments and student or personal loans under debt; do not count purchases in both living expenses and debt payments.
Does this still work with the 50/30/20 rule?
You can use 50/30/20 as a rough target: 50% of take-home income for needs, 30% for wants and 20% for savings and extra debt repayment. This planner uses your actual category totals instead of automatically assigning those percentages.
Should my budget start with gross or net income?
Use after-tax take-home income for this planner. That keeps taxes and payroll deductions already removed from your paycheck from being counted twice.
Where should annual bills go?
Either divide each annual bill by 12 when using monthly entries, or enter all amounts yearly. Keep the selected basis consistent across the entire form.