Kids’ Birthday Party Planner

How I worked this out

• Food: quantities start from a 2-hour party for 6–8 year olds, then scale. Under-3s get about 60% of that, 3–5s about 80% and 9–12s about 125%. Longer parties scale up and shorter ones down. Parties over a mealtime get about 30% more savoury food. Siblings are counted in the food.
• Allergy swaps: each child with a dietary need gets their own portion of an allergy-friendly version of any food that wouldn’t suit them. I assume no overlap between needs, so you may end up with a couple spare.
• Cake: sizes assume small party-size slices, one per guest including siblings and grown-ups.
• Bags and hats: one for every invited child and sibling, plus 1 spare.
• Tableware: 2 plates and 2 cups per person (one for food, one for cake, and cups go missing), 3 serviettes each, plus about 10% spare.
• Wrapping paper: based on a 70 cm-wide roll, with pieces sized for a small gift (about 8 × 6 × 4 cm), a picture book (about 20 × 15 × 2 cm) or a craft kit (about 30 × 20 × 6 cm), plus 10% for mistakes.
• Balloons: one bunch of 3 at each end of every kids’ table, assuming about 8 kids per table, plus 20% spare (at least 2) for pops.
• Ice: about half a kilo per person for drinks and the esky on a warm day.
• Run sheet: splits your party length into blocks that suit the age. Treat the times as a guide, as kids rarely stick to the schedule.
• Budget: bags come out first, then the rest is split using a typical breakdown for your setting. It’s a starting point, so move money around to suit you.