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”
Average candy – snickers bar – the one i have here at my desk is roughly 50g and has 230Cals.
0.45kg=~9X230=~2000Cals/lb of candy.
A snickers bar like that may cost about $1.30 at a convenience store but given that most of the ones bought for halloween will be bought in larger quantities at maybe half the price ($.75) a 1lb bag of candy might be about 10 bars, so about $7.
$2.7billion/$7=~$2.8B/$7=400million lbs of candy (that’s more than 1lb/person!!!). Note that it is ~$7 or 2000Cal/lb.
$2.7B in candy =~400Mlbs*2000Cal/lb= 800 Billion Calories.
(Talking about same calories as defined but note that strictly scientifically, 1cal=4.2J, 1kcal=1000cal=1Cal=4.2kJ (here in problem defined as “calories”, or “food calories”.)
Assuming ~300million people in the US, that is 1.33lbs/person. I think it is safe to round that to actual 1lb *consumed*, considering typical wastage of food in the US (unpopular, lost, expired, and otherwise spoiled candy). So each person may be eating on average of ~1lb of candy more, which is about 2000Cals, resulting in a bit over 1/2lb (2/3.5) of weight gained by every person., or about 150million lbs gained total among all of US population.
This does not assume additional candy consumption from prior purchases not included in the $2.7B spent strictly for Halloween as some may purchase candy ahead of time or use/reuse other candy on Halloween that was bought for other purposes.
Total Spending on Candy: $2.7B
1. Average Candy Cost, segmented into budget and premium:
Budget: 100 candies @ $3 = $0.03 per candy
Premium: 100 candies @ $15 = $0.15 per candy
Average = $0.09 per candy
2. Average calories per candy (fairly standard regardless of budget/premium):
5000 calories for a typical box of 100 candies = 500 calories per candy
3. Number of candies purchase = $2.7B total candy spending / $0.09 cost per candy = 30B candies purchased
4. Total caloric intake if ALL candies purchased are consumed:
30B candies x 500 calories = 15 Trillion calories consumed
5. Weight gain:
3,500 calories = 1 pound
15 trillion = approximately 4B pounds gained
TOTAL WEIGHT GAINED BY AMERICAN POPULATION: 4 BILLION LBS
1.37 Kg per person
411 million lbs
60,000,000 pounds of weight gained
Assume that “fun size” candy bars are the most common candy given out, and that they also represent a good middle ground between smaller, less caloric candies and larger full-size bars.
$2.7B dollars x 1 bag/$4 x 20 pieces/1 bag x 150 cal/1 piece x 1 lbs/3500 cal =
Approximately 579 million pounds
Another option for removing candy from your kid is something called the “Switch Witch”. You allow the kid to take out a small number of pieces, say 10, and then have them put the rest out in a bowl. In the night, the Switch Witch visits, much like Santa Claus or the Tooth Fairy, and switches the bowl of candy for some small toy the kid wants.
There was $2.7B spent on candy. Lets assume that all of the candy purchased came in the assorted bags of candy for ease of computation. Those assorted bags of candy average $10/ bag and 100 pieces of candy per bag. Lets say each piece of candy averages out to 70 calories per piece. So we get 7,000 calories per bag of $10 candy. We know that there is 3500 calories per pound, so we’ll say eating one bag of candy causes a gain of 2 lbs.
Given there was $2.7B spent in total that givens us 270M bags of candy at $10/bag. So the math would say that if each bag causes a gain of 2 lbs and every single one of the 270M bags of candy is consumed, that would cause a gain of 540M lbs! Looking at a 10% adjustment to account for variations in the number of candy in a bag or calories per piece of candy I would say buying purchasing and consuming $2.7B worth of candy would lead to combined weight gain of around 496M to 594M lbs in total!
Hi Victor,
To give a short answer:
$ spent = 2,700,000,000.00 (given)
$/candy = $0.50 (estimate)
n of candies = 5,400,000,000.00 (calculated)
calories/candy = 80.00cal (estimated)
calories consumed = 432,000,000,000.00cal (calculated)
calories/quilo = 7,777.78cal/kg (given)
quilos gained in the US = 55,542,857.14kg (calculated)
population US = 322,761,807.00 (census 2016)
quilos gained per person = 0.17kg (calculated)
% of waste (best date, loss, no sufficient kids to get them, etc…) = 20% (estimate)
quilos gained per person (final) = 0.14kg (calculated)
pounds per american = 0.3 pounds (converted)
Best regards
463 MM lbs
Assumptions:
1. American population above 5 years old – 304m (Census Bureau)
2. Average calorie in $1 candy – 400 calories
3. All $2.7 b candy is consumed by “someone” American population – i.e. Not exported
4. Average weight gain – 3500 calories = 1lb
Calculations:
Total calories in the $2.7b worth of candy = 1 trillion calories (154k tons) – assumption point 2
Total Weight gain by population = 308M lbs (Assumption point 4)
Estimated weight of the American population = 1.01lb per an American (Total weight gain/Total population older than 5years)