It uses simple percentage math
Each category is calculated as monthly spending multiplied by the editable rate shown in the form. The calculator does not know your lease, tax return, insurance policy, credit agreement, or local prices.
It is not a legal or financial recommendation
The result is a planning prompt. Do not rely on it for loans, taxes, insurance purchases, investments, benefits, debt settlement, or any decision where accuracy has legal or financial consequences.
It can be customized
If you have a rent renewal notice, insurer quote, utility notice, or lender statement, replace the default percentage with your real change. That makes the estimate more useful for your household.