Quick guide
How to use this calculator
- Choose one time period and one currency, then enter every amount using that same basis.
- Use zero when a listed category does not apply; do not leave required fields empty.
- Read the primary result together with its component totals and the visible scope notes.
Calculation method
Calculation method
Money left = regular after-tax income + other income − monthly spending − planned savings and investments.
Entered decimals are combined with exact integer-and-rational arithmetic. Results round to two decimal places for ordinary money display, while a smaller nonzero value remains visible instead of being shown as zero. Repeating percentage digits appear in parentheses; an ellipsis marks a decimal expansion longer than the 12-place preview.
Worked example
Worked example
With 4,000 of after-tax income, 100 of other income, 3,100 of spending, and 500 of planned savings, the plan leaves 500.
Money left = regular after-tax income + other income − monthly spending − planned savings and investments.
Supported inputs
Precision and limits
Visible input limits
Amounts accept up to 30 digits and 12 decimal places and are capped at 1e12 in magnitude. Scientific notation and grouped thousands separators are rejected.
International scope
No currency, tax system, benefit definition, debt limit, accounting standard, or recommended household ratio is assumed.
Planning boundary
The result is a mathematical summary of entered amounts, not financial advice, a credit decision, a tax calculation, or a legal balance sheet.
Calculator-specific assumptions
Use amounts from the same month. Irregular expenses should be converted to a monthly amount if you want them included.