It's not rocket science
/ɪts nɒt ˈrɒkɪt ˈsaɪəns/informalUK · US
What does “It's not rocket science” mean?
It's not rocket science means that something is not difficult to understand or do.
“It's not rocket science” tells someone that a task is fairly simple to understand. It can still take time, care or practice.
The phrase can reassure a nervous beginner, but it can also make someone feel foolish for struggling. Your tone makes a big difference.
When do people say it?
Use it informally to reassure someone about a manageable task or criticise unnecessary complication.
“You just match the labels to the boxes; it's not rocket science.”
Is it formal or informal?
Register: informal. It is most at home in everyday conversation rather than formal writing. Most common in UK and US.
Where does it come from?
Rocket science is a familiar example of difficult technical work. Comparing an everyday task with it makes the task sound much simpler.
Origin confidence: Disputed; treat with caution
How do you say “It's not rocket science” in other languages?
Related idioms
- A piece of cake, Extremely easy.
Last updated 2026-09-16