Examples
Examples
Try the starting example
- Opening cash balance ($)
- 100
- Income received each week ($)
- 0,200,0
- Recurring spending each week ($)
- 60,60,60
- One-off fees each week ($)
- 0,0,150
- End-of-week balances ($)
- 40, 180, -30
- Lowest end-of-week balance ($)
- -$30.00
- First shortfall week
- 3
- Additional opening cash to avoid end-week shortfalls ($)
- $30.00
Try another scenario
- Opening cash balance ($)
- 150
- Income received each week ($)
- 0,200,0
- Recurring spending each week ($)
- 60,60,60
- One-off fees each week ($)
- 0,0,150
- End-of-week balances ($)
- 90, 230, 20
- Lowest end-of-week balance ($)
- $20.00
- First shortfall week
- None
- Additional opening cash to avoid end-week shortfalls ($)
- $0.00
Calculation method
Calculation method
End-of-week balances ($)
Opening balance plus cumulative weekly income minus recurring costs and one-off fees.
Lowest end-of-week balance ($)
Minimum of opening balance and all end-of-week balances.
First shortfall week
First one-based week ending below zero, or None.
Additional opening cash to avoid end-week shortfalls ($)
max(0, negative of the lowest opening/end-week balance).
Symbols and units
- a
- Opening cash balance ($)
- b
- Income received each week ($)
- c
- Recurring spending each week ($)
- d
- One-off fees each week ($)
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Assumptions & limits
Assumptions & limits
- A loan-free cash ledger in one currency. Assumes income is available before that week’s expenses; it cannot reveal within-week cash shortages or predict spending.
Are these inputs private?
These calculations run in your browser. A shared link contains the values you choose to share. Only questions submitted to the separate AI finder are sent to OpenAI.
Further reading
OpenStax: arithmetic and geometry ↗
Background reading; this does not imply endorsement or independent review of SumFizz.