Quick guide
How to use this calculator
- Enter one scenario using a consistent currency and the periods shown by each label.
- Keep targets, coverage time, income basis, and expected return aligned with your own planning definition.
- Read the result with the visible assumptions before using it in a financial decision.
Calculation method
Calculation method
Target reserve = essential monthly expenses × selected coverage months + additional one-time reserve; funding gap = max(target − current reserve, 0).
Exact decimal/rational arithmetic is used for cash-flow totals. The savings-goal projection uses stable logarithmic compounding with a zero-rate limit and rejects overflow or a nonzero result that would become zero. Repeating ratios use parentheses; an ellipsis marks a preview longer than 12 decimal places.
Worked example
Worked example
Essential expenses of 2,000 for 4 months plus a 1,000 one-time reserve produce a 9,000 target; 3,000 already saved leaves a 6,000 gap.
Target reserve = essential monthly expenses × selected coverage months + additional one-time reserve; funding gap = max(target − current reserve, 0).
Supported inputs
Precision and limits
Visible input limits
Amounts accept up to 30 digits and 12 decimal places and are capped at 1e12. Rates are capped at 1000%; whole-month horizons are capped at 1,200, with 120 months for reserve coverage and sabbatical duration.
International scope
No currency, country, benefit system, recommended fund size, guaranteed return, or savings-rate standard is assumed.
Planning boundary
Results are deterministic projections of entered assumptions, not guarantees, investment advice, or a judgment about an adequate reserve.
Calculator-specific assumptions
There is no universal reserve amount. Coverage time, likely one-time shocks, accessibility, and what counts as essential depend on the household, so every assumption is entered by the visitor.