Off the top of my head means from memory, straight away and without checking. People say it when they answer quickly and can't promise they are exactly right: they give a rough figure, a date or a name. In IELTS Speaking it's a handy way to start an answer when you don't have exact data. It isn't used in essays, where approximately fits better.
When would you say off the top of my head?
Write a sentence — we'll check that the expression fits the situation and suggest what to fix.
The check is taking longer than usual. Your feedback will appear here automatically.
off the top of my/your head; I can't + remember/tell you + noun + off the top of my head; Off the top of my head, I'd say + clause
- Off the top of my head, I'd say the trip will cost about three hundred euros.
- I don't know her phone number off the top of my head, but it's in my emails.
- Can you name three French painters off the top of your head?
What changed
First versionI can't tell you the exact price from the top of my head.
RevisionI can't tell you the exact price off the top of my head.
From may seem logical, since the answer comes from your memory. But the idiom needs off: off the top of your head. No other preposition works here. The correction replaces from with off.
Don't confuse it with by heart. By heart means from memory, exactly and in full: I know the poem by heart. Off the top of my head is rough and comes with no guarantee: Off the top of my head, about forty people came.
Your turn
I haven't got the timetable with me, but ___, the last train leaves at about eleven.
Show the answer
off the top of my head — The speaker doesn't have the timetable, and about shows that the time is only approximate. That's an answer off the top of my head. By heart means “word for word, from memory”, so it suggests exact knowledge, and it usually follows know: I know it by heart.
A colleague or friend asks you for a figure you don't remember exactly. Write your reply with off the top of my head: give a rough number and say where the exact figures can be checked.
Off the top of my head, we have about sixty clients in Spain, but the exact number is in the sales report.
Learn to use new words without mistakes
Write phrases with the words you are learning. LetsWords shows mistakes in usage and grammar, suggests corrections and explains them, and review helps the words stick.