Quick answer: Both mean something incorrect, but mistake = careless or unintentional slip, usually personal: I made a mistake in the test. Error = more formal, systematic, or significant deviation from what is correct, used in technical, academic, and scientific contexts: There is an error in the code. The most important collocation: you make a mistake/error — not “do” one. For a fuller definition, see the Cambridge Dictionary entry for ‘mistake’.
Comparison Table
| Word | Part of Speech | Meaning | Example |
|---|---|---|---|
| mistake | noun | careless or unintentional wrong action; personal slip | I made a mistake in the test. / spelling mistake |
| error | noun | formal or systematic deviation from what is correct | There is an error in the code. / margin of error |
Using Mistake — Everyday Carelessness and Personal Slips
Mistake is the everyday word for getting something wrong, usually through carelessness, inattention, or misunderstanding. It is personal and informal in feel. You use it for a spelling mistake, a driving mistake, or making a mistake in an exam. The word implies a human, often minor, slip — something that happened because a person was not careful enough or did not know better at the time.
I made a mistake in my calculations.
Sorry — I picked up the wrong bag by mistake.
She made several spelling mistakes in the email.
It was a mistake to leave without saying goodbye.
Common Phrases with Mistake
Knowing the key collocations will help you use mistake naturally and avoid one of the most common errors English learners make — using the wrong verb.
- make a mistake — the standard collocation; never say “do a mistake”
- by mistake — accidentally, without intending to: “I deleted the file by mistake.”
- mistake of doing something — “It was a mistake agreeing to that contract.”
- learn from your mistakes — a common phrase encouraging improvement from past errors
- make the same mistake twice — to repeat an error you have already made once
Don’t make the same mistake again.
I sent it to the wrong address by mistake.
It was a mistake agreeing to that contract.
Using Error — Formal, Technical, and Systematic Contexts
Error is preferred in formal, technical, scientific, and legal writing. It often implies a more significant or systematic deviation rather than a simple careless slip. Where mistake suggests a person being careless, error suggests a failure in a process, system, or judgement that may have wider consequences. In computing, science, statistics, and law, error is the expected, standard term.
The software returned an error message.
The margin of error in the survey was ±3%.
Scientists identified a systematic error in the experiment.
The pilot corrected the navigational error immediately.
Error in Formal and Legal Language
Several important collocations require error rather than mistake — they are fixed expressions that cannot be swapped. Understanding these is essential for formal writing, academic English, and professional communication.
- error of judgement — a poor decision rather than a factual mistake
- in error — formally meaning wrongly or by accident (used in legal and official contexts): “The payment was made in error.”
- trial and error — a method of achieving a goal by trying different approaches and learning from failures
- human error — a mistake caused by a person rather than a machine (fixed phrase; never “human mistake”)
- error rate — the frequency of errors in a process or system
- rounding error — inaccuracy introduced by rounding numbers
Note that in formal writing, in error is used where everyday speech would say by mistake: “The payment was made in error.”
The accident was attributed to human error.
The decision was reversed after an error of judgement.
The amounts were calculated by trial and error.
Side by Side: Mistake vs Error
These parallel examples show exactly how the two words differ in practice — the same situation can be described with either word, but the choice changes the register and nuance significantly.
She made a mistake in the exam. — personal, careless slip
The exam paper contained a printing error. — formal, systematic fault in the paper itself
He sent it to me by mistake. — everyday, careless
The parcel was delivered in error. — formal/legal language
Common Mistakes
✗ I did an error in my homework.
✓ I made an error in my homework.
The correct verb is make, not do. This applies to both mistake and error: make a mistake, make an error.
✗ Less appropriate: The researchers found a mistake in the data.
✓ More appropriate: The researchers found an error in the data.
Error is the expected term in academic and scientific contexts; mistake sounds informal in these registers.
✗ Less common: I sent it by error.
✓ More natural: I sent it by mistake.
By mistake is the standard everyday phrase. In error is the formal/legal equivalent — but “by error” is non-standard in both registers.
Also confusing: Look vs Seem, Problem vs Issue, Reason vs Cause, Affect vs Effect. Browse all confusing word pairs →
Quick Check: Mistake or Error?
Four questions — choose the correct word or phrase for each sentence.
1. “Sorry, I sent that email ___ to you.”
2. “The lab found a systematic ___ in the measurements.”
3. “He made a ___ when he forgot her birthday.”
4. “The computer displayed an ___ message.”
Frequently Asked Questions
What is the difference between mistake and error?
Both refer to something done incorrectly, but they differ in register and context. Mistake is the everyday word for a careless or unintentional slip, especially personal: “I made a mistake in the exam.” Error is more formal and is preferred in technical, scientific, legal, and academic contexts: “There is an error in the data,” “margin of error,” “error message.” In everyday speech, mistake is far more common; in formal writing, error is often expected.
Do “mistake” and “error” mean exactly the same thing?
They overlap significantly, but they are not always interchangeable. Both can describe something done incorrectly, but error tends to imply a more formal or systematic deviation, while mistake often implies a personal or careless slip. In technical writing, error is standard (“software error,” “human error”). In everyday conversation, mistake is more natural (“I made a mistake”). Either word works in many contexts, but choosing the right one for the register matters.
What verb do you use with “mistake” and “error”?
Both collocate with make: “make a mistake,” “make an error.” Never use “do a mistake” or “do an error” — this is one of the most common errors made by English learners. “Make” is the correct verb: “She made a serious error of judgement.” / “Don’t make the same mistake again.” The verb “commit” is sometimes used formally: “commit an error,” though “make” is more natural.
What does “by mistake” mean? How is it different from “in error”?
“By mistake” is the everyday phrase meaning accidentally or unintentionally: “I deleted the file by mistake.” “In error” is the formal or legal equivalent: “The payment was made in error” (used in official correspondence or legal documents). Both mean the same thing — an unintentional action — but “by mistake” is used in speech and informal writing, while “in error” belongs to formal registers.
What is “human error”?
“Human error” is a fixed phrase in formal and technical English meaning a mistake caused by a person rather than a machine or system. It is extremely common in official reports, accident investigations, and technical analyses: “The crash was caused by human error.” Note: you would not normally say “human mistake” — error is the standard word in this phrase. This illustrates how some collocations are fixed and cannot be swapped freely.
What is “margin of error”?
“Margin of error” is a statistical term referring to the range within which the true result is expected to fall. It is used in surveys, polls, and scientific research: “The poll showed 52% support, with a margin of error of ±3%.” This is always “margin of error” — never “margin of mistake.” It is one of many technical collocations that require error rather than mistake.
Can you use “mistake” in academic or scientific writing?
It is better to use “error” in academic and scientific writing. Peer-reviewed papers, lab reports, and technical documents use “error” as the standard term: “measurement error,” “systematic error,” “random error,” “error analysis.” Using “mistake” in these contexts can sound informal or imprecise. In general academic writing (essays, arguments), “mistake” is acceptable: “It would be a mistake to assume...”
What is the difference between “make a mistake” and “commit an error”?
Both mean to do something wrong. “Make a mistake” is by far the most common everyday phrase. “Commit an error” is more formal and often used in sports, law, and formal writing: “The defender committed a costly error.” “Commit” tends to imply a more deliberate or significant action. For everyday contexts, “make a mistake” is always safe and natural.
What is “trial and error”?
“Trial and error” is a fixed phrase meaning a method of achieving a goal by trying various approaches and learning from each failure: “She learned to play the piano by trial and error.” It always uses “error” — “trial and mistake” is not standard English. This phrase is used across contexts from everyday problem-solving to scientific methodology.
How do “mistake” and “error” appear in IELTS writing?
In IELTS Task 2 (academic essays), “error” is the more formal choice and is preferred: “It is an error to assume that...” / “Systematic errors in policy...” “Mistake” is also acceptable in academic writing but can sound slightly informal. Both collocate with “make”: “make an error,” “make a mistake.” Avoid “do an error/mistake” — this is a common mistake that costs marks. In Task 1 data description, “error” is expected in statistical contexts (margin of error, measurement error).