Examples
Examples
Try the starting example
- Issued items: name, issue date, selected life days, replacement $ each, quantity
- Shirt,2026-10-01,30,20,2 Shoes,2026-07-22,90,50,1
- As-of date
- 2026-10-20
- Forward budget horizon days
- 14
- Replacement due dates
- Shirt: 2026-10-31; Shoes: 2026-10-20
- Replacement cost due by horizon ($)
- $90.00
- Straight-line accrued replacement reserve ($)
- $75.33
- 30-day equivalent ongoing reserve ($)
- $56.67
Try another scenario
- Issued items: name, issue date, selected life days, replacement $ each, quantity
- Shirt,2026-10-01,30,20,2 Shoes,2026-07-22,90,50,1
- As-of date
- 2026-10-20
- Forward budget horizon days
- 0
- Replacement due dates
- Shirt: 2026-10-31; Shoes: 2026-10-20
- Replacement cost due by horizon ($)
- $50.00
- Straight-line accrued replacement reserve ($)
- $75.33
- 30-day equivalent ongoing reserve ($)
- $56.67
Calculation method
Calculation method
Replacement due dates
Issue date + supplied planned life days.
Replacement cost due by horizon ($)
Sum replacement costs whose due dates are at or before as-of+horizon, including overdue items once.
Straight-line accrued replacement reserve ($)
For each item cap elapsed/life at 1, then multiply by replacement value × quantity.
30-day equivalent ongoing reserve ($)
Sum(value × quantity / selected life days) × 30.
Symbols and units
- a
- Issued items: name, issue date, selected life days, replacement $ each, quantity
- b
- As-of date
- c
- Forward budget horizon days
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 reserve ledger from your chosen replacement lives, not a prediction of wear or growth. Accrual is capped at one replacement per issued item; the 30-day equivalent is not a calendar-month forecast.
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.