Your guess is as good as mine
/jɔːr ɡɛs ɪz əz ɡʊd əz maɪn/informal, neutralUK · US · AU · IE · CA
What does “Your guess is as good as mine” mean?
Your guess is as good as mine means i do not know the answer any more than you do.
This phrase means that you do not know the answer to a question. It shows that you and the other person have the exact same amount of information, which is none.
It is a friendly and natural expression. People often use it in daily conversation instead of just saying "I don't know."
When do people say it?
People say this when someone asks them a question and they have no idea what the answer is.
“"Why is the train late today?" "Your guess is as good as mine."”
Is it formal or informal?
Register: informal, neutral. It is most at home in both everyday conversation and professional writing. Most common in UK and US and AU and IE and CA.
Where does it come from?
The phrase became common in American English in the early twentieth century. Its exact inventor is not known.
Origin confidence: Reasonably documented
How do you say “Your guess is as good as mine” in other languages?
Last reviewed 2026-09-11