Decision-Making Biases
Planning fallacy
Underestimating how long work will take.
What Is Planning fallacy?
Planning fallacy is a thinking trap where underestimating how long work will take.
How It Tricks You
It can make one option feel obvious before the tradeoffs have been checked.
Real-World Example
A weekend closet project quietly becomes a three-week project.
Seen Online As
- This should only take an hour.
- We will finish faster this time because we know what we are doing.
- The best-case timeline feels like the realistic one.
What To Ask Instead
How long did similar work actually take before?
Related Thinking Traps
Common Situations
Quick FAQ
What is Planning fallacy?
Underestimating how long work will take.
What is an example of Planning fallacy?
A weekend closet project quietly becomes a three-week project.
How do I spot Planning fallacy?
How long did similar work actually take before?