The traffic estimate. Households × children per household × the share who walk to your door. On a through-street in a town, 50–70% of local children is a reasonable share; on a cul-de-sac or a road with no pavements it can be half that. Weather moves it more than anything else: a dry, mild evening can double the queue, and heavy rain can empty the street by eight o'clock.

Buying. Pieces needed is visitors × sweets per visitor × (1 + spare). Bags are rounded up, because you cannot buy two-thirds of a bag. The spare allowance covers latecomers and the neighbour's children who arrive with their cousin — 10–20% is usually enough, and unused sealed bags keep until next year.

The peak hour. Most door traffic is not evenly spread. If 40% of visitors arrive in the busiest hour, that hour alone needs 40% of the pieces within reach. Keep a second bowl in the hall rather than a single giant one by the door, so refilling does not mean leaving the doorway unattended.

What it does not do. It does not estimate sugar, calories or cost per child's bag, and it cannot tell you what the neighbours are giving out. It also cannot plan for allergies: keep wrapped sweets with readable ingredient labels, and offer a non-food alternative in a separate bowl so a child with an allergy is not handed something they have to refuse in front of their friends.

Leftovers and next year. Sealed bags keep for months in a cool cupboard; opened bags go soft within a week or two. Buy the spare in sealed bags rather than opening a large one early, and keep a small bowl of non-food treats — stickers, glow sticks, temporary tattoos — alongside the sweets. The Teal Pumpkin Project exists for exactly this reason: a visible alternative means a child with a food allergy gets a choice instead of a polite refusal.

Last reviewed: 2026-10-20. A shopping estimate, not a safety or nutrition assessment; check every wrapper's allergen information before offering it.