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”
$2.7b sales/$27 per bag = 100m bags
Split 50/50 into 50m chocolate and 50m non chocolate.
50m bags * 6 lbs./choc bag = 300m chocolate lbs.
50m bags * 4 lbs./non choc bag = 200m non-choc lbs.
Segment chocolate into 20/75/5 fats, sugars, and fillers with no caloric value respectively. Segment non-chocolate into 80/20 sugar and fillers
Then we have 40m/150m in fats and sugars for chocolate, and 240m lbs. sugar in non-chocolate, for 40m lbs. fat and 390m lbs sugar.
40m lbs fat * 454 g/lb * 9 cal./gram fat = 160b fat cal
390m lbs sugar * 454 g/lb * 4 cal./gram sugar = 720b sugar cal.
160b fat cal 720b sugar cal = *** 880b total cal ***
880b total cal/3500 cal. per lb. = *** 250m lbs. gained ***
Approximately 200 million pounds.
total sales $2 700 000 000
av.price of 1 candy $1
av.weight of 1 candy 1,6oz
calories per 1 candy 235
calories bought 396 562 500 000
lb gained per 3500 cal 1lb
Total lbs gained by American population 113 303 571 lb
Overview
To estimate the total number of pounds gained from the given variables, I will use the following formula:
Total pounds gained = Total calories / Calories per 1lb gain (given)
= (Total # of candy * Calorie per candy) / 3500
= [(Total spend on candy/Price per candy) * Calorie per candy] / 3500
Segmentation
There are two unknowns in the formula above: Price per candy and calorie per candy. To find this I would segment into two types of candy – Segment (1): Chocolate Segment (2): Sweets.
Given this segmentation, let me break down the numerator in the formula above into two segments:
Total pounds gained= [(Spend on candy / Price per candy P) * Calorie per candy C] / 3500
= [(Spend on seg (1) / P(1) * C(1) ) (Spend on seg (2) / P(2) * C(2) ) ] /3500
Estimates for unknown variables
Now let’s plug in the unknowns from external sources (footnoted at bottom)
Spend on seg (1) = 75% of 2.7bn ~ 2bn
P(1) = 5
C(1) = 220 calories per serving * 15 servings = 3300
Spend on seg (2) = 25% of 2.7bn ~ 0.7bn
P(2) = 5
C(2) = 160 calories per serving * 17 servings ~ 2650
Putting it together
Total pounds gained= (2bn/$5 *3300 0.7bn/$5 *2650) /3500
~485k pounds (total for America’s 330 m people, total in 2016 Halloween period)
Answer: 485k pounds
**Note: This segmentation of candy categories is based on the hypothesis that these two candy groups represent the largest variation in calorie per candy – fats vs sugar. Price per candy, however, is more/less the same (i.e. way too cheap i.e. does not price externalities of diabetes)
**Assumptions: I will use unit prices for the most common packets that people will be buying (Walmart halloween top sellers) to standardize for how many candies are actually exchanged for each dollar people are paying.
**External sources used: 2013 survey from National Confectioners Association, Walmart store listings
$2.7 billion in Candy
3,500 calories equals 1 pound
In my experience, the calorie count and cost of chocolate differs from “non-chocolate” candy, so I am going to segment this market. For chocolate, I will assume that 2000 calories costs roughly $5. For non-chocolate candy, I will assume it’s a bit more expensive (complicated to produce, maybe), so let’s say that 1000 calories is equal to $1.
I will assume for simplicity that the $2.7 billion is divided such that $1.5 billion is spent on chocolate, while the remaining $1.2 billion is spent on non-chocolate candy.
According to my estimate, $1.5 billion in chocolate is 1.5 trillion calories. $1.2 billion in non-chocolate is 480 billion calories.
This gives us a total of 1.98 trillion calories. Divided by 3,500 calories gives us 565,715 pounds.
The American population will gain 150 Million pounds of weight
Assuming each candy is 0,5kcal and that each candy cost 0,5$. We will have that, in the US there will be 5.4 billions of candy sold which are equivalent of 2,7billions of kcalories.
Therefore, since 3,5kcal is 1lib, the total amount gained in weight will be 770Millions liber (approximatively).
Top candies given out for Halloween:
Reese’s Peanut Butter Cups: 210 Calories
M&M’s: 240
Snicker’s 250
Chocolate Bars: 220
Kit Kat: 210
Twix: 345
3 Musketeers: 240
Milky Way: 240
Almond Joy: 220
Total Calories Estimate: 556,587,900,000
556,587,900,000 / 3,500 =
Total Pounds Estimate: 159,025,114.29 (160 Million)
*I conducted a few more calculations not shown here, I did my homework : )
In addition to assuming all candy is consumed and 3,500 calories results in 1 lb of weight gain, let’s assume three things:
The average fun-size (i.e., small) piece of candy contains 80 calories.
The average bag of candy contains 20 fun-size pieces.
The average price for a bag of candy is $5.00.
So:
To determine the total number of bags sold, divide the total amount spent on candy ($2.7 billion) by $5 (the average cost of a bag of candy) and we get 540 million bags of candy.
To determine the total calories consumed, multiply the number of pieces of candy in each bag (20) by number of calories in each piece (80), then multiply that number by the number of bags sold (540 million) and we get 864 billion calories (20x80x540,000,000).
To determine the total weight gain within the American population following this calorie consumption, divide the total calories consumed (864 billion) by the caloric equivalent of 1 lb (3,500) and we get 246,857,142.9 (rounded to 246,857,143), representing the total weight in lbs.
Given:
$2.7 billion in candy (9 x $300 million)
3,500kcal = 0.45kg gain
Assume that (i) on average people give away poor quality candy as they don’t want to invest in something that is just given away -> $9 = 2kg of candy
(ii) 300 million people eating candy in USA (makes calculations simpler)
total of 600 million kg candy consumed
-> everyone consumes 2kg
assume that on average candy has 350kcal/100g -> 2kg = 7,000kcal
->everyone consumes 7000kcal
->everyone gains 0.9kg
——————-
Thus total calorie consumption is 2,100 billion kcal and the total gain 270 million kg from halloween candy