Budget a birthday party by venue, food and activities.
A children's party splits neatly into fixed and variable costs, and knowing which is which changes the decisions. Venue hire, the entertainer and the cake are fixed — the same for twelve guests or twenty-five. Food and party bags are per head, and here total 15 dollars a guest. That means the all-in cost per guest falls as the list grows, which is the opposite of the intuition that leads parents to trim the guest list: cutting three children off a 15-guest list saves 45 dollars, not a fifth of the party. If the budget is the problem, the fixed items are where the money is.
Birthday Party Planner
Variable = guests x (food + party bag); fixed = venue + entertainer + cake; total = variable + fixed; all-in per guest = total / guests
A common guide is the child's age plus one for younger children. Beyond that, remember the marginal cost per guest is small — it is the venue and entertainer that set the budget.
Party bags and decorations, because both are bought in a hurry. Setting a per-bag figure in advance and sticking to it is the single most effective control.