Birthday Theme Planner for Themed Party Lunches

Every quantity on the list comes from the head count, so the list is a shopping list rather than a mood board. The reasoning is simple and worth knowing, because it is the part most parents get wrong when they guess.

• Balloons run at two per child, which is enough for a balloon arch and still leaves enough for each child to hold one without the room turning into a balloon shop.
• Banner strings run at one per four children, so eight children get two strings and a wall of about two metres each. One long string for eight children is always too sparse.
• Plates get one extra, because the extra plate holds the cake and the serving spoon, and every party runs into that problem at 3 pm.
• Cups get two extra, for the adults and for a second drink, and napkins get two per child because the first one always goes missing.
• Confetti squares run at five per child, which is enough to look like a celebration and small enough to sweep up in five minutes afterwards.
• Goodie bags are one per child, and two tablecloths appear once you pass eight children, because one cloth cannot cover two tables.

At the default of eight children that is 16 balloons, 2 banner strings, 9 plates, 10 cups, 16 napkins, 40 confetti squares, 8 goodie bags and 2 tablecloths. Every one of those numbers moves when the head count moves.

The birthday child and the guests get different lunches on purpose. The hero plate is themed, because it is the one photograph and the one thing the child will talk about. The guest plate is a craft lunch, because children who are handed a plate of identical sandwiches sit still for two minutes while children who are handed components to assemble sit still for fifteen.

• The hero plate is 432 calories at the standard portion: bread, turkey, cheddar, lettuce, carrot sticks, an apple, a juice box and the themed cookie.
• The guest plate is about 180 calories and $1.35, built from crackers, cheddar cubes, grapes, apple slices and a carrot pouch.
• The age setting scales the hero plate, not the guest plate. Under 5 the plate is scaled to 0.6 with round fruit cut into quarters; 9 to 12 goes up to 1.25 with a second fruit portion and a second juice box.
• The themed cookie is the only item that changes the shape of the food. Everything else on the hero plate is a normal lunch that will not be refused because it looks unfamiliar.

The cost difference is worth noticing too: the hero plate at $2.13 and seven guest plates at $1.35 each comes to $11.58 for the food, before the cake and the lemonade. A themed party lunch is not the expensive part of a party.

The breakdown has four lines, and the order of the lines tells you something. Food is the biggest line, decoration is small, and the line most people forget is disposables: napkins, goodie bags and tablecloths together come to more than the balloons and the banner ever do.

• At eight children with a homemade cake, food is $27.88, decoration $5.38, plates and cups $4.35 and disposables $10.44, for a total of $48.05 against a $60 ceiling.
• The cake is the single biggest item at $14.50 homemade against $28.00 bought, so that one decision moves the total more than every decoration combined.
• Goodie bags at 60 cents each are the easiest line to cut, and they are also the line most likely to be missed if you skip them, so the cuts list puts them second.
• One tablecloth instead of two saves $2.50, and printed plates you already own save about $3.15 without anyone noticing a change.
• Whatever is left over is better spent on food than on decoration. A dessert table at $1.50 a child turns the remaining $11.95 into something the children talk about afterwards.

The cost model is honest about its limits: these are average US prices for standard quantities, and a party shop in December will not sell them at these numbers.