It can be tricky buying treats at Halloween. Buy too little and you risk breaking the hearts of young princesses and superheroes; too much, and you’re going to be saddled with all those calories for yourself.

But a new tool could help.

Vancouver-based mathematician Jens von Bergmann has created two new online interactive maps on the CensusMapper he created with colleague Alejandro Cervantes.

The first map estimates “trick-or-treater density” – meaning the number of kiddies per square kilometres in your area.

The other measures “trick or treat onslaught” – which reveals the number of “trick or treat children per (haunted) dwelling” in your neighbourhood.

The darker the orange on the map, the more kiddies will probably be knocking on your door.

Both tools use data from the latest census data, focusing on children aged 5 to 14. That’s “prime trick-or-treating age," according to Statistics Canada.