What is the primary goal of Fermi Estimation?

The goal is to reach an order-of-magnitude approximation (within a factor of 10) for a complex quantity using minimal data and logical decomposition.

Why is breaking the problem down important?

Decomposition allows you to estimate individual factors you are more familiar with; since some estimates will be high and others low, the errors often cancel out in the final product.

When should I avoid using Fermi Estimation?

Avoid using it for life-critical decisions, precise legal/contractual figures, or scenarios where a 10x error would have catastrophic consequences.

How does this skill help with software development?

It allows developers to perform quick sanity checks on architectural decisions, such as estimating how much storage or bandwidth a feature might require before building it.

Fermi Estimation Thinking Pattern

Name: Fermi Estimation Thinking Pattern
Author: lev-os

bylev-os

0•

Productivity & Workflow

Decomposes complex, unknown quantities into smaller, estimable parts to reach order-of-magnitude accuracy for quick decision-making.

The Fermi Estimation skill provides a structured framework for tackling 'unknowable' numerical problems—from market sizing to engineering capacity planning—when precise data is unavailable. By guiding Claude through a process of logical decomposition, the skill breaks down overwhelming questions into simple, estimable variables where errors tend to cancel each other out. This approach is essential for high-level strategic thinking, performing sanity checks on detailed projections, and making rapid 'go/no-go' decisions without getting bogged down in exhaustive research.

Key Features

01Refinement workflows for tightening estimates based on key facts

02Built-in sanity checking against known reference classes

030 GitHub stars

04Order-of-magnitude calculation logic with aggressive rounding

05Sensitivity analysis to identify high-impact assumptions

06Structured problem decomposition into 3-7 estimable variables

Use Cases

01Performing back-of-the-envelope engineering sanity checks for system load

02Determining resource requirements and staffing needs for speculative projects

03Estimating Total Addressable Market (TAM) for new product features

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add lev-os/agents fermi-estimation

For use in Claude.ai and ChatGPT

Download Skill