Idiom
Burn the midnight oil
By EasySay. Published . Updated .
Burn the midnight oil means to keep working or studying far into the night, often to finish something on time.
It does not mean you use real oil. People say it about an essay, a report or a busy week. It sounds friendly and a little tired, and you will hear it in Australia, the UK and the US.
Written for EasySay, in our own words.
In short
- AvoidIt does not mean using real oil.
- Or sayWork late
Burn the midnight oil: what it is, and what it is not
- IS
- Working or studying late into the night, often to meet a deadline.
- IS
- Longman labels it informal.
- IS NOT
- About burning lamp oil in the middle of the night: it means working late.
Meaning: To work or study late into the night, often to meet a deadline.
How do people say it?
- In conversation:
I had to burn the midnight oil to finish my essay.
- At work:
The team will burn the midnight oil this week to meet the deadline.
Check yourself
What should I know?
The words say
To burn lamp oil in the middle of the night.
It really means
To work or study late into the night.
What do dictionaries say?
- In Australia
- Longman labels it informal. The dictionaries we checked give it no Australian label, so it is general English, not only from Australia.
- In the UK
- The dictionaries we checked give it no British label, so it is general English, not only from the UK.
- In the US
- The dictionaries we checked give it no American label, so it is general English, not only from the US.
What mistakes should I avoid?
- Use it for late at night. Do not use it for working during the day or for one extra hour.
- It does not mean using real oil. People say it even when they use a computer.
- In the past, say “burned” or “burnt”. Both are correct; “burnt” is more usual in Australia and the UK.
The phrase works with different times: “I burn the midnight oil”, “we burned the midnight oil”, “she is burning the midnight oil”. The important word is “midnight”. It makes the idea about late hours, not about long hours in the day.
People often add a reason after it: “to finish the report”, “before the exam”, “for the deadline”. The reason makes the meaning clear for a listener who does not know the phrase.
It is a good phrase for work or study, because it shows effort without complaint.
A manager who says, “Thank you for burning the midnight oil on this project,” is praising hard work.
It is also useful for a friend who is tired: “You look tired. Were you burning the midnight oil?”
Be careful not to use it as an order. “You must burn the midnight oil” can sound like a demand, so ask or thank instead.
Imagine a house before electric lights. A person sits at a table with a lamp, and the lamp needs oil. While the town sleeps, the lamp burns and the person keeps working.
You do not need to know the history to use the phrase; the picture is enough. Today the lamp is a screen, and the phrase has stayed, because the feeling of working while others sleep has not changed.
What else can I say?
- Work late Plain and clear. People say “We are working late tonight.”
- Stay up late working Plain. It adds that you also lose sleep.
- Pull an all-nighter Mainly American and casual. It means staying up the whole night to study or work.
More idioms
- Under the weather Feeling a little unwell or tired, not at your best.
- Bite the bullet To face something hard or unpleasant and get on with it, because you cannot avoid it.
- Once in a blue moon Very rarely; something that happens only now and then.
- Hit the sack To go to bed, usually because you are tired.
More examples
- In a text:
Going to burn the midnight oil tonight, so I will text you tomorrow.
Questions people ask
Does “burn the midnight oil” mean I use oil?
No. It is a picture from the days of oil lamps. Today people use it for any work or study that goes late into the night.
Is it a good thing or a bad thing?
Both are possible. It can show hard work, and it can show a tired person. The words around it tell the listener whether the speaker is proud or worried.
Can I use it for an early morning start?
No. The idiom is about the late hours before or after midnight. For an early start, say “start very early” or “get up early to work”.
Sources and dates
- EasySay's own writing for the idioms, EasySay. Licence: original writing for EasySay. Checked .
- Longman Dictionary of Contemporary English: usage labels, Pearson Education. Licence: our own words, from the facts in the source. Checked .
Cite this page
EasySay. "Burn the midnight oil". https://easysay.org/idioms/burn-the-midnight-oil. Last updated 23 October 2026.
https://easysay.org/idioms/burn-the-midnight-oil