Examples
Examples
Try the starting example
- Participants: name, arrival date, departure date
- A,2026-10-20,2026-10-23 B,2026-10-21,2026-10-23
- Shared expense pool ($)
- 100
- Common supply units per person-night
- 1.5
- Person-nights by participant
- A: 3; B: 2
- Time-weighted shared expense ($)
- A: 60; B: 40
- Total supply units
- 7.5
- Peak concurrent overnight participants
- 2
- Total person-nights
- 5
Try another scenario
- Participants: name, arrival date, departure date
- A,2026-10-20,2026-10-23 B,2026-10-20,2026-10-23
- Shared expense pool ($)
- 100
- Common supply units per person-night
- 1.5
- Person-nights by participant
- A: 3; B: 3
- Time-weighted shared expense ($)
- A: 50; B: 50
- Total supply units
- 9
- Peak concurrent overnight participants
- 2
- Total person-nights
- 6
Calculation method
Calculation method
Person-nights by participant
Departure date − arrival date, with arrival inclusive and departure exclusive.
Time-weighted shared expense ($)
Allocate the common expense pool in whole US cents by relative person-nights, largest remainders and input-order ties.
Total supply units
Total person-nights × supplied units per person-night.
Peak concurrent overnight participants
Count participants present each night across the entered range.
Total person-nights
Sum individual person-nights.
Symbols and units
- a
- Participants: name, arrival date, departure date
- b
- Shared expense pool ($)
- c
- Common supply units per person-night
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 person-night allocation under your chosen shared-cost rule, with no inference about actual individual use. Same-day attendance is excluded by this overnight model; dates are civil dates without time zones.
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.