Event budgets: which costs change with guest numbers?
More guests may leave the venue fee unchanged. Dividing an old budget by attendance and multiplying by new attendance can therefore mislead: not every cost scales with the crowd.
Fixed or per person?
Classify venue and equipment using the actual quote; calculate refreshments per guest only when priced that way. Itemized costs make choices clearer than an unexplained total. Suppliers need not use the same charging model.
Keep each row on the same basis
Enter each item’s full cost. At 25 per guest for 40 guests, enter 1000 and put the calculation in notes. Do not add a per-person price to a whole-venue fee as though they were comparable units.
Before sharing the sheet
Compare your total with your chosen spending limit, a general budgeting approach supported by consumer.gov. State important assumptions and excluded costs, then print the version agreed by organizers. A budget is not an event safety plan or permit.
References: Federal Trade Commission — Making a Budget
Example: another 10 guests
Venue 600, equipment 200 and refreshments 40 × 25 = 1000 total 1800. For 50 guests: 600 + 200 + 1250 = 2050 if other prices stay unchanged.
The increase is 250, not the 450 obtained by raising the whole old budget by 25%. Check package limits or a larger-room charge before relying on this scenario.