THE NUMBERS, EXPLAINED
How to use this calculator.
All household members share the same assumed attendance rate for an expected-count scenario. Full RSVP capacity is checked separately; fractional expectations are not seat assignments.
Start with your inputs
Enter invited children by household, invited adults by household, venue guest capacity, assumed attendance rate (%). Keep amounts in the units shown on each field. The example is a starting point, not a recommended value.
| Input | Example value |
|---|---|
| Invited children by household | 2,1,3 |
| Invited adults by household | 1,2,2 |
| Venue guest capacity | 12 |
| Assumed attendance rate (%) | 80 |
A worked example
With the example inputs above, children and adults invited is 6, 5. Change the inputs to explore your own scenario.
| Result | Example answer |
|---|---|
| Children and adults invited | 6, 5 |
| Maximum invited guests | 11 |
| Expected attendance | 8.8 |
| Full-attendance capacity margin | 1 |
How this is calculated
Children and adults invited
Add children and adult counts separately.
Maximum invited guests
Add all children and adults.
Expected attendance
Apply supplied attendance percentage.
Full-attendance capacity margin
Subtract all invited guests from venue capacity.
Symbols and units
- a
- Invited children by household
- b
- Invited adults by household
- c
- Venue guest capacity
- d
- Assumed attendance rate (%)
Use the units shown. A list keeps the order in which you enter its values. The symbol ^ means “raised to the power of”.
Assumptions and limits
All household members share the same assumed attendance rate for an expected-count scenario. Full RSVP capacity is checked separately; fractional expectations are not seat assignments.
Calculations use the values you enter. Blank or invalid inputs show an error instead of silently substituting zero. Results are displayed to useful precision; calculations retain the underlying numeric precision.
Questions about this tool
What does the result tell me?
Children and adults invited; Maximum invited guests; Expected attendance; Full-attendance capacity margin. The result applies to the method and inputs described above. Check the units and assumptions before using it in a decision.
Why might another calculator differ?
Differences in units, rounding, timing or model definitions can produce different answers. Compare the input definitions and the method, rather than only the final number. For this tool: All household members share the same assumed attendance rate for an expected-count scenario. Full RSVP capacity is checked separately; fractional expectations are not seat assignments.
Are my inputs stored or sent to AI?
Calculations on this page happen in your browser. The separate AI question finder sends its submitted conversation to OpenAI; these calculator fields are not sent. Favourites and recent tool names are stored locally. A shared link contains the inputs you choose to include.
Further reading
OpenStax: Solve proportions and their applications ↗
Background reading; this does not imply endorsement or independent review of SumFizz.
Review status
Software example and browser checks are recorded in our quality report. No external expert review is claimed. Created with coding assistance; calculations run as ordinary browser code.
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