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Start with money that actually arrives
Use household take-home income, not gross salary. For weekly amounts multiply by 52 and divide by 12; for fortnightly amounts multiply by 26 and divide by 12. Four weeks is not an average month. If work varies, try both a typical month and a lower-income month.
Give irregular bills a monthly place
List housing, groceries, transport, utilities, insurance and debt payments. Add annual car registration, school costs and other predictable bills separately. Divide the annual total by twelve to find a monthly reserve. Avoid counting the same bill as both a monthly cost and an annual bill.
Read the two balances
Income less spending is the cash available before saving. Subtract the planned savings allocation to find unallocated cash. A deficit means the inputs do not fit together; it is not a judgement about the household. If essentials exceed income, information about concessions, payment support and free financial counselling may be more useful than a savings target.
A worked month
$6,000 take-home less $2,000 housing, $1,800 living costs, $300 debt and $300 for annual bills leaves $1,600 before saving. A $600 savings allocation leaves $1,000. The $3,600 annual bills are being reserved for, not an extra $3,600 spent every month.
Turn the plan into a review habit
Compare one month of actual transactions with the plan. Separate predictable annual costs from genuinely unexpected emergencies. Check whether household transfers or credit-card repayments double-count purchases already listed. Revisit the plan after changes in rent, hours, dependants or loan rates.
Try it, then question it
Change one input at a time. Explain why the result moved before changing another. Compare your answer with the worked example and read the exclusions before relying on any estimate.
Model boundaries
Monthly net income; annual bills divided by 12. Savings are an allocation, not consumption. Enter each cost once: mortgage in housing, other loans in debt. Income tax is already deducted. No bank connections or recommended spending percentages.
References and verification
Official references checked for this release on 1 November 2026. Rules and product terms can change.