What is the fermi problem-solving strategy?

Benjamin Landry
3 min readDec 29, 2020

What is a fermi problem and what does it mean to fermi-ize it?

A fermi problem is a category of problems that require estimations and assumptions to solve. It tends to be creative or out-of-the-box questions. To fermi-ize a problem involves solving a problem with the fermi problem-solving strategy. The essence is to breakdown a large and broad question into its smallest elements. At which time, each element would be solved for. Then, all the elements would be accumulated to produce a conclusion.

When I discovered this technique it radically changes my ability to resolve creative problems my mind would invent as a potential project. Now that I use it, I think about problems differently. I am able to focus on tangible elements that are solvable, instead of using only my gut feeling assumptions.

How to pose a good fermi question?

The goal of the question should be clear and the outcome should be a quantity. The questions should not be impossible, unknowable and unpredictable. For example, “who will win the Super Bowl in 2050?” or “will the stock market go up or down tomorrow?”

Good Fermi Example are:

  • How many times could you say the alphabet in 24 hours?
  • How many ping pong balls would it take to fill the classroom?

How do you solve a fermi problem?

Once you have determined the problem that you want to solve. Follow the following process:

  • Write the key terms that regards the problem
  • Write the smallest questions needed to solve the problem
  • Write assumptions made and facts found, regarding the smallest questions
  • This step involves researching for information, to solve the smallest questions
  • Write and perform calculations using the facts & assumptions
  • Generate a point form conclusion that provides an answer to the original problem

What value does fermizing a problem provide?

Benjamin Landry

I spend my time dreaming about food, watching fictional characters go through adventures, and think of creative ideas to improve the future.