You'll get access to over 3,000 product manager interview questions and answers
Recommended by over 100k members
- CLARIFY:
- Is it OK to focus on individual consumers v. businesses / hotels, etc. purchasing toilet paper? Yes.
- Is it OK to focus on direct to consumer purchases v. secondary retailers? Yes.
- Is it OK to focus on actual need v. customers hoarding toilet paper (as we saw during the beginning of COVID)? Yes.
- EQUATION: Total Market Size of Toilet Paper = # Toilet Paper Users X Average toilet paper use / user
- BREAKDOWN EQUATION:
- # Toilet Paper Users:
- Total Population in US: ~330M
- Total Users of Toilet Paper:
- Average Lifespan: 0-80 Years
- Average # of People / Age Year:
- Assume even distribution of people / year.
- 330M / 81 = ~4.1M assuming
- Total Users of Toilet Paper:
- Assume babies (under 1 year old) don't use toilet paper. Use diapers instead.
- Total Users of Toilet Paper: 4.1M people / age year * 80 years = 328M people
- Gender Split:
- Assume 50% of population is Male v. Female.
- 328M / 2 = 164M males and 164M females using toilet paper
- Average Sheet / User:
- Average Day / User: Assume individuals are awake ~ 8AM - 10 PM = 14 hour day. (May be variation by age but total hours awake shouldn't vary too drastically. Children will sleep longer than adults who stay up late but should even out.)
- Female Bathroom Usage: Based on personal life observations, assume that women go to the bathroom more than men. Additionally, assume they use toilet paper for both No. 1 and No. 2. Assume women go to the bathroom every 2 hours. 14 hour day / 2 hours = 7x / day
- No. 1 Toilet Paper Usage:
- Assume 6/7 times a woman goes to the bathroom, she is going No. 1.
- Assume each No. 1 visit requires 4 sheets of toilet paper.
- 6 visits / day * 4 sheets / visit = 24 sheets / day.
- No. 2 Toilet Paper Usage:
- Assume 1/7 times a woman goes to the bathroom, she is going No. 2.
- Assume each No. 2 visit requires 30 sheets of toilet paper.
- 1 visit / day * 30 sheets / visit = 30 sheets / day.
- Total Female Toilet Paper Usage / Day: 24 sheets for No. 1 + 30 sheets for No. 2 = 54 sheets / day
- No. 1 Toilet Paper Usage:
- Male Bathroom Usage: Assume men go to the bathroom less frequently than women / day. Assume they only use toilet paper for No. 2. Assume men go to the bathroom every 3 hours. 14 hour day / 3 hours = ~4.7 > round to 5x / day.
- No. 1 Toilet Paper Usage:
- Assume 4/5 times a man goes to the bathroom, he is going No. 1.
- Assume no toilet paper is used for No. 1.
- No. 2 Toilet Paper Usage:
- Assume 1/5 times a man goes to the bathroom, he is going No. 2.
- Assume each No. 2 visit requires 30 sheets of toilet paper.
- 1 visit / day * 30 sheets / day = 30 sheets / day.
- Total Male Toilet Paper Usage / Day = 0 sheets for No. 1 + 30 sheets for No. 2 = 30 sheets / day.
- No. 1 Toilet Paper Usage:
- # Toilet Paper Users:
- EQUATION TOTAL:
- Total Sheets / Year:
- Female Population Total Sheets:
- 164M women * 54 sheets / day = 8.9B sheets / day
- 365 days / year * 8.9B sheets / day = 3.2T sheets / year
- Male Population Total Sheets:
- 164M men * 30 sheets / day = 4.9B sheets / day
- 365 days / year * 4.9B sheets / day = 1.8T sheets / year
- Total Population Total Sheets: 3.2T sheets / year for women + 1.8T sheets / year for men = 5T sheets / year
- Female Population Total Sheets:
- Total Rolls / Year:
- Assume 50% of the population uses 1 ply rolls and 50% uses 2 ply rolls. (Assume the type of toilet paper didn't change the sheet usage.) 5T sheets per year / 2 = 2.5 T sheets per 1 ply roll and 2.5 T sheets per 2 ply roll.
- 1 Ply Total Rolls Total:
- Assume 1 Ply Roll = 1000 sheets
- 2.5T sheets / 1000 sheets per roll = 2.5B 1 ply rolls
- 2 Ply Total Rolls Total:
- Assume 2 Ply Roll = 500 sheets
- 2.5T sheets / 500 per roll = 5B 2 ply rolls
- Total Market Size:
- Assume 1 ply rolls cost $1 / roll
- Assume 2 ply rolls cost $2 / roll
- (2.5B 1 ply rolls * $1 / roll) + (5B 2 ply rolls * $2 / roll) = $12.5B total market size
- Note: Some users may occasionally use toilet paper to clean up a spill and use it as Kleenex. May go through toilet paper rolls more quickly, so could increase total cost by ~10% = $13.75B / year total market size.
- Total Sheets / Year:
- ASSUMPTIONS:
- There could be a smaller portion of the population that has disabilities and may require a larger toilet paper use or some of the population may use extreme amounts of toilet paper in a single use (i.e. grabs a handful from the roll). Could increase market size.
- Parents don't use toilet paper on their babies (more likely to use b
Quick calculation
- US population 340M
- TP users is ~90% = 300M (rest use bidets or are infants who are in diapers)
- 1 person uses ~2 rolls a month which is 24 rolls a year
- 300M people will need (300*24) ~7.2 billion rolls per year
- 12 pack TP roll cost = ~$20
Total Market = (7.2 billion / 12 ) *$20 —> ~$12 billion per year
240M use toilet papers. It’s safe to say that each person uses one roll per week. This means about 50 rolls per year per person. There is not much distinction between age group/gender so it’s straight up multiplication and 12B is the market size for TP in the US per year. Since each roll costs about $1, 12B is also the market cap.
Sanity check-wise, this is reasonable. (looks like the number is similar to Anita)
It says it’s 12.128B so it’s actually quite close.
To estimate the market size of toilet paper in the US, I will first estimate the number of toilet paper rolls used in the US per year and then multiply that number by an estimated price of one roll.
Let’s start with the easy one: price of one toilet paper roll in the U.S.. A box containing of 12 rolls of 200 sheet toilet paper is usually around $12 so the cost of a single 200-sheet role is around $12/12=$1.
To estimate the number of toilet paper rolls used in the US, I will break down the usage to 3 age demographics of 3 to 10, 10 to 60, and 60 to 80. I will also assume population of the US is 320million and the population is evenly distributed in the age range of 0 to 80, meaning that there are 320M/80 = 4M people that share the same age year.
Here is a quick table to estimate volume of toilet paper used per day in the US.
age group 3 to 10: 3 times per day. each time 6 sheets. total number of sheets used per day in this age group is: 7 years x 4M people per age year x 3 usages per day x 6 sheets per usage =504M sheets per day or 504M/200=around 2.5 million rolls
age group 10 to 60: 2 times per day. each time 12 sheets. total number of sheets used per day in this age group is: 50 years x 4M people per age year x 2 usages per day x 12 sheets per usage= 4,800M sheets per day or 4,800/200=24M rolls per day
age group 60 to 80: 1 time per day. each time 10 sheets. total number of sheets per day in this age group is : 20 years x 4M people per age year x 1 usages per day x 10 sheets per usage = 800M sheets per day or 800/200=4M rolls per day
Total number of rolls per day = 2.5M+24M+4M = around 30million rolls per day
Total number of rolls per year = 30 million x estimated 350 days per year = 10,500 million rolls per year
Given price of $1 per roll, total market size is 10,500 million rolls per year x $1 per roll = $10.5 B
I made a set of assumption to solve this problem : number of sheets per roll, average price of one roll, number of times people in an age group use a toilet paper, number of sheets used per age group.
Top Google interview questions
- What is your favorite product? Why?89 answers | 263k views
- How would you design a bicycle renting app for tourists?62 answers | 82.5k views
- Build a product to buy and sell antiques.54 answers | 66.8k views
- See Google PM Interview Questions
Top Estimation interview questions
- Calculate the number of queries answered by Google per second.45 answers | 78.5k views
- How do you decide how many cash registers you need for a new Walmart store?33 answers | 39.4k views
- How many dentists are there in New York?33 answers | 36.7k views
- See Estimation PM Interview Questions
Top Google interview questions
- How would you improve Google Maps?53 answers | 228k views
- A metric for a video streaming service dropped by 80%. What do you do?50 answers | 135k views
- How would you design a web search engine for children below 14 years old?36 answers | 42.9k views
- See Google PM Interview Questions
Top Estimation interview questions
- Estimate the number of Uber rides.30 answers | 51.3k views
- Estimate the number of bicycles required to start a bike sharing operation in a big city.18 answers | 15.8k views
- Estimate the number of WhatsApp chats occuring in India.14 answers | 13.3k views
- See Estimation PM Interview Questions