Well, a new survey seems to have found the answer.
Researchers in New Jersey crunched the numbers and found that, on average, people say kids should stop going door-to-door for candy at 13 and a half years old.
The researchers at Farleigh Dickinson University surveyed more than 800 people across the country.
The average response across age, racial and ethnic groups, and even the political divide, came to that cap of 13 and a half years.
However, researchers also found that younger votes and left-leaning Americans are more likely to say that children should be able to trick-or-treat at any age.
The poll took on another hot Halloween topic as well.
According to the poll, 12% of respondents plan to give out full-size candy bars.
But mini-size is still the norm, with 46% giving out "fun-sized" candy.
2% said they'll hand out non-food items, and 33% are not handing out any treats this year.