Both phrases are correct. They are not interchangeable, though. The difference is word order, and word order depends on the kind of sentence you are writing.
The short answer
- Use how long does it take when you are asking a direct question.
- Use how long it takes when the phrase sits inside a statement or inside another question.
Direct question:
- How long does it take to boil an egg?
Inside a statement:
- I know how long it takes to boil an egg.
Why the word order changes
A direct question puts the helper verb (does, do, did, will) before the subject. That is why we say “How long does it take?”
When the same question becomes part of a longer sentence, it stops being a question. It turns into a plain piece of information, and the subject comes first again. So “does it take” becomes “it takes.”
| Direct question | Inside a longer sentence |
| How long does it take? | I don’t know how long it takes. |
| How long did it take? | She told me how long it took. |
| How long will it take? | Tell me how long it will take. |
| How long do they take? | Check how long they take. |
Notice that the helper verb does disappears when the question moves inside a sentence. The main verb carries the “s” instead (takes). In the past tense, did take becomes took.
When to use “how long does it take”
Use it when the sentence itself is a question and “how long” opens it.
- How long does it take to get a passport?
- How long does it take to learn Spanish?
- How long does the bus take to reach the airport?
It also works inside quotation marks, because the quoted words are still a direct question:
- She asked, “How long does it take?”
When to use “how long it takes”
Use it when the phrase is part of a larger sentence and the sentence is not a question about the time itself.
After verbs like know, wonder, tell, ask, and depend on:
- I wonder how long it takes to get to the station.
- The website tells you how long it takes to ship an order.
- She asked me how long it takes to bake bread.
As the subject of a sentence:
- How long it takes depends on the traffic.
- How long it takes to recover varies from person to person.
After polite question openers:
- Can you tell me how long it takes?
- Do you know how long it takes to renew a license?
The last pair is the one that trips people up. These sentences end in a question mark, but the “how long” part still uses statement order, because it is tucked inside the polite opener.
A simple test
Ask yourself: is “how long” starting the sentence, or is it in the middle of one?
- Starting the sentence as a question? Use does it take.
- In the middle of a sentence, after words like know, tell me, wonder, or depends on? Use it takes.
Common mistakes
Mistake: I don’t know how long does it take.
Correct: I don’t know how long it takes.
Mistake: Can you tell me how long does it take to get there?
Correct: Can you tell me how long it takes to get there?
Mistake: How long it takes to charge this phone?
Correct: How long does it take to charge this phone?
The first two mistakes keep question order inside a statement. The third does the opposite and uses statement order in a direct question.
You may hear “I wonder how long does it take” in casual speech. Most editors and teachers still treat it as an error, so avoid it in writing.
Other tenses and subjects
The same rule works with any tense or subject.
- How long did the meeting take? → I forgot how long the meeting took.
- How long will the repair take? → Ask them how long the repair will take.
- How long do these tablets take to work? → Read how long these tablets take to work.
- How long does the trip take? → Nobody knows how long the trip takes.
Does “take” need a person?
You can add a person to either form:
- How long does it take you to get ready?
- I know how long it takes me to get ready.
Without the person, the sentence still works and sounds more general.
Quick takeaway
Write how long does it take when you are asking. Write how long it takes when you are telling, wondering, or explaining. If a word like know, tell, or wonder comes before “how long,” drop does and use it takes.
Read more about these:
- I Miss You All vs I Miss You Guys Too: What’s the Difference?
- Where Do You Live vs Where Do You Reside: What’s the Difference?
- Time Constraint vs Time Constraints: Which One Should You Use?
- Which Is Better vs Which One Is Better: What’s the Difference?
- Appreciate It vs Appreciated It: Which One Should You Say?
I write clear, practical English lessons for everyday use. On Lingotexting, I break down grammar, vocabulary, and word types into simple ideas you can apply quickly. My focus is accuracy, real examples, and helpful visuals, so learners build confidence, improve writing, and communicate naturally in school, work, and daily life.