Last night, I took my kids out for an American children’s holiday known as Halloween.
Kids (and some ahem… adults) dress up in costume (I was a penguin this year), go door-to-door, saying “Trick or Treat” and get free candy from the neighbors.
My three kids brought back a record 420 pieces of candy. 
In today’s New York Times, I learned that in the weeks leading up to this holiday, Americans purchased $2.7 BILLION dollars in candy.
So here’s my challenge for you.
Assuming all of that candy is consumed by someone in America, estimate the total number of calories represented by $2.7 billion in candy.
Assuming 3,500 calories consumed results in a person gaining 1 lb (0.45 kg) in weight, estimate how many pounds (or kilograms) of weight the American population will gain. Add a comment below to post your entry.
The winner will receive public acknowledgement of their estimation skills, and I will send them a portion of the candy “tax” I collected from my kids.
Yes, we tax our kids for a portion of their candy collection, as mom and dad provide “infrastructure” and “chaperone” services.
It’s a useful lesson in taxation.
(We tax at a 33% tax rate.)
Mostly it is an excuse to reduce the amount of sugar they will otherwise end up consuming.
For my kids, it’s an excuse to get rid of the candy they don’t like anyways.
Good luck and Happy Halloween!
Entries will be accepted for next 72 hours, and only entries posted as comments below will be considered. A winner will be announced next week.
UPDATE as of Friday, November 4TH AT 12PM ET: New entries are welcome, but not eligible to win, as contest has closed.
329 thoughts on “A Sweet Estimation Question”
Hi Victor,
In order to estimate the total number of pounds the population will gain from $2.7B lbs of candy, we’ll assume that the vast majority of this candy is sold in the form of fun-size bags. Each fun-size bag sells for about $5 and contains 1 lb of candy. Thus, there were about 540M fun-size bags sold for Halloween.
Fun-size bags come in many varieties but generally, they tend to be chocolate candies and each chocolate candy is 40-80 calories each, so we’ll assume 60 calories each on average. A typical candy (for example, snicker’s fun-size) might weigh perhaps 1/10 of a lb, so there are 10 in each bag. Thus, each bag is 600 calories each.
Therefore, the total number of calories consumed is 600 * 540M = 324B. There are ~3,500 calories in a pound, so therefore the number of pounds would be ~92.5M. This number is an underestimate when compared to the US population of ~320M, suggesting ~.3 lbs/person. However, this weight gain probably disproportionately affects kids and candy lovers.
If average candy bar price is $1.30, then Americans purchased around 2B pieces of candy ($2.7B / $1.30). If then average number of calories per candy bar is ~250 kcal, then Americans purchased in total 520 trillion in calories. If we divide it by 3500kcal (the number needed to gain 0.45kg) and multiply by 0.45 kg, we learn that in total, Americans will gain 66 million kg in weight. If there are approx. 323 730 000 Americans, then if everyone eats a fair portion of the candy, each American will gain approx. 0.2kg in weight after Halloween.
Assuming average calories per dollar among all kinds of candy is 320 cal/$, according to Hershey dark chocolate’s specification and price. So, 320 * 2.7 * 1000,000,000/3500= 246857142 lbs. which is the total weight gain if all the candy of 2.6B has been consumed in a day, without considering the simultaneous consumption of calories by our body. This seems a lot heavy weight, but if we average it into our USA population (324,897,733 as of October 2016), it is only 0.76lb gain for each people living in USA. But this would never happen, so don’t be fool think you will only gain less than 1 pound after eating a full basket of Hersheys.
The current population of the United States of America is 324,904,135 as of Tuesday, November 1, 2016, based on the latest United Nations estimates. 324,904,135 *0.45 = 146,206,860.75 kg in total
A candy bar costs about 40 cents and has about 200 calories. This translates to 500 calories per dollar spent.
2.7 billion dollars spent means there are 1.35 trillion calories.
If consuming 3,500 calories results in a person gaining 1 pound, then the American population will gain approximately 386 million pounds (or 175 million kg). With a population of 330 million, this means on average every American gains 1.17 pound.
Assuming that each candy piece costs a quarter dollar ($0.25), those $2.7 Bn would equal 10.8 Bn pieces of candy. Reese’s cups have an estimated amount of 250 cal per piece (‘serving’), so if we assume that as an average of cals/piece, we multiply times pieces and we get 2700 Bn calories. Divide by 3500 cal/lb and we get an overall weight gain of 0.77 Bn lbs, which is equal to 2.41lbs/capita if the US population is around 320 million
Assuming one candy pack to be costing US$2.7 effectively resulting in 1 bn packs of candy being sold with an average of 25 candies in each pack, population will approximately gain a 178 million pounds collectively (again assuming 70% of the population consumes or can consume candy) at an average 25 calories per candy
roughly 308M lbs the American population will gain as a result of the Halloween candy, or roughly 1 lb per person in the United States.
100 calories/candy
$.25/candy
94,537,815 pounds
Approximately 60 million pounds in total.