Assign every dollar of your monthly income to a category — enter your income and spending groups to see what's allocated and what's still left to budget.
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Results
Calculated
Total allocated
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Sum of all budget categories
Left to budget
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Income minus total allocated (goal: $0)
Savings & debt rate
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Share of income going to savings/debt
Needs rate
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Housing + food + transportation as % of income
Ready
Enter your monthly income and category amounts, then press Calculate.
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How zero-based budgeting works
A zero-based budget assigns every dollar of income a specific job before the month begins. The core rule is simple: Income minus Total Allocated equals zero. Nothing is left "unbudgeted" — money that isn't spent on bills is deliberately assigned to savings, debt payoff, or another named category instead of drifting into random spending. This calculator adds up the categories you enter and shows exactly how much is left to assign so the total lands on zero.
The formula
Enter your monthly take-home income and how much you plan to put toward housing & utilities, food & groceries, transportation, savings & debt payoff, and everything else (subscriptions, fun money, and any other spending). The calculator sums the five categories into Total Allocated, then computes Left to Budget = Income minus Total Allocated. In a true zero-based budget that number is $0. A positive number means you have income with no job yet; a negative number means you've assigned more than you actually earn.
Understanding the inputs
Every category should be a planned amount, not a guess — pull housing and transportation from your actual bills, and treat savings & debt payoff as a required line item rather than whatever happens to be left over. That habit is what separates zero-based budgeting from a budget that just tracks spending after the fact.
Interpreting the results
Total Allocated and Left to Budget are the two numbers that define whether the budget is truly zero-based. Savings & debt rate and Needs rate are informational context: they show what share of income is going toward savings/debt and toward the housing-food-transportation "needs" group, useful for comparing against a guideline like the 50/30/20 rule even though zero-based budgeting itself doesn't require fixed percentages.
Frequently Asked Questions
What is zero-based budgeting?
Zero-based budgeting is a method where you assign every dollar of income to a category before the month starts, so that Income minus Total Allocated equals zero. Nothing is left unassigned: money not spent on bills goes into savings, debt payoff, or another named category instead of sitting unbudgeted.
What does it mean if my Left to Budget number isn't zero?
A positive Left to Budget means you have income with no job yet — move it into savings, debt payoff, or another category. A negative number means your categories add up to more than your income, so you're over-allocated and need to reduce a category (often discretionary spending) until the total matches your income exactly.
How is zero-based budgeting different from the 50/30/20 rule?
The 50/30/20 rule sets fixed target percentages for needs, wants, and savings. Zero-based budgeting doesn't prescribe percentages at all — it only requires that every dollar of income be assigned somewhere so the total allocated equals total income. You can use 50/30/20 as a starting guideline and still build the budget zero-based.
Should savings and debt payoff count as a budget category?
Yes. In zero-based budgeting, savings and debt payoff are treated as required expenses with their own line item, not as an afterthought of whatever is left over. That is what keeps the remaining balance at zero instead of money drifting to unplanned spending.