Have you ever typed “4rth” and paused to wonder whether it actually looks right? You’re not alone. Many people get confused about is it 4rth or 4th, especially when writing ordinal numbers such as “fourth.”
The correct form is 4th. “4rth” is incorrect because the ordinal form of four is “fourth,” and its standard numerical abbreviation is 4th, not 4rth.
Whether you’re writing about a 4th floor, 4th year, 4th anniversary, or another ordinal position, 4th is the form you should use.
Is It 4rth or 4th?
The correct spelling is 4th.
- 4th — Correct
- 4rth — Incorrect
The number 4 is written as four, while its ordinal form is fourth. When abbreviated numerically, “fourth” becomes 4th.
For example:
- I live on the 4th floor.
- She is in her 4th year of university.
- Today is our 4th anniversary.
- He finished in 4th place.
The extra r in “4rth” does not belong in the abbreviation.
4rth or 4th: Which Is Correct?
If you’re wondering 4rth or 4th which is correct, the answer is straightforward: 4th is correct.
The confusion usually comes from looking at the full spelling “fourth.” Because “fourth” contains an r, it can seem logical to put that letter into the numerical abbreviation. However, ordinal abbreviations don’t work by simply taking every letter from the written word.
For example:
| Number | Ordinal word | Correct abbreviation |
| 1 | first | 1st |
| 2 | second | 2nd |
| 3 | third | 3rd |
| 4 | fourth | 4th |
| 5 | fifth | 5th |
| 6 | sixth | 6th |
| 7 | seventh | 7th |
| 8 | eighth | 8th |
| 9 | ninth | 9th |
| 10 | tenth | 10th |
Notice the pattern: 4th follows the standard ordinal-number abbreviation.
What Is the Meaning of 4th?
The term 4th means fourth. It indicates that something occupies position number four in an ordered sequence.
For example, consider these positions:
- First
- Second
- Third
- Fourth
So, 4th = fourth = number four in a sequence.
This is called an ordinal number. Ordinal numbers describe position, rank, order, or sequence rather than quantity.
For comparison:
- 4 = cardinal number, indicating quantity
- 4th = ordinal number, indicating position
You might have four books, for example, but if one book is next in a particular sequence, it could be the 4th book.
Why Is “4rth” Incorrect?
The mistake comes from combining the number 4 with part of the spelling of fourth.
Someone might reason that because fourth contains “rth,” the abbreviation should be 4rth. But standard English doesn’t form ordinal abbreviations that way.
The correct abbreviation uses the number 4 followed by the appropriate ordinal ending:
4 + th = 4th
The form 4rth is therefore a misspelling or nonstandard form.
You may occasionally see “4rth” in casual texts, usernames, social media posts, or informal online writing, but that doesn’t make it grammatically correct.
4rth or 4th Floor: Which One Should You Use?
When referring to a building level, use 4th floor, not 4rth floor.
Correct:
My office is on the 4th floor.
Incorrect:
My office is on the 4rth floor.
You can also write the number out completely:
My office is on the fourth floor.
Both 4th floor and fourth floor are correct. The choice usually depends on the writing style and context.
For formal documents, directions, or polished prose, spelling out the ordinal may sometimes look more natural. In signs, addresses, forms, schedules, and everyday writing, 4th floor is perfectly normal.
4rth or 4th Year?
The correct expression is 4th year or fourth year.
For example:
She is currently in her 4th year of university.
Or:
She is currently in her fourth year of university.
Both forms communicate the same thing.
However, avoid writing:
She is in her 4rth year.
The abbreviation remains 4th, regardless of the noun that follows it.
4rth or 4th Anniversary?
When celebrating four years of a marriage, relationship, business, event, or other occasion, the correct form is 4th anniversary.
For example:
Happy 4th anniversary!
You can also write:
Happy fourth anniversary!
Both are grammatically correct.
4rth anniversary, on the other hand, is incorrect.
This same rule applies to other ordinal-number expressions, such as:
- 4th birthday
- 4th wedding anniversary
- 4th celebration
- 4th edition
- 4th attempt
- 4th chapter
- 4th position
When Should You Write “Fourth” Instead of “4th”?
Although 4th is correct, sometimes spelling out fourth is preferable.
In general writing, especially when you’re aiming for a polished or formal style, spelling out numbers can make a sentence flow more naturally.
For example:
The fourth chapter explains the main concept.
This can feel more formal than:
The 4th chapter explains the main concept.
However, numerical abbreviations are common in practical contexts:
- 4th floor
- 4th Avenue
- 4th place
- 4th quarter
- 4th grade
- 4th year
The appropriate choice can depend on the style guide, publication, or type of document you’re writing.
How Do Ordinal Number Abbreviations Work?
Ordinal numbers tell us where something falls in a sequence.
The most common numerical endings are:
- 1st — first
- 2nd — second
- 3rd — third
- 4th — fourth
- 5th — fifth
- 6th — sixth
- 7th — seventh
- 8th — eighth
- 9th — ninth
- 10th — tenth
The first three are slightly unusual because they use st, nd, and rd.
After that, th is used for most ordinal numbers.
That’s why we write 4th, not 4rth.
Examples in Sentences
Here are some everyday examples:
- We live on the 4th floor.
- This is my 4th attempt.
- She came in 4th place.
- He is in his 4th year of college.
- The company’s 4th anniversary is next month.
- Read the 4th chapter before answering the questions.
- This is the 4th edition of the book.
Is “4rth” Ever Correct?
In standard English, no. If you’re using the number four as an ordinal abbreviation, 4th is the accepted standard form.
You might encounter 4rth online, but it is generally the result of a spelling mistake, typing error, or informal usage.
If you’re writing something that needs to look professional—such as an email, academic assignment, résumé, report, invitation, or business document—stick with 4th.
4rth or 4th? A Quick Memory Trick
Having trouble remembering the correct form?
Think of the word fourth and focus on its ending:
fourth → th
Now replace “four” with the numeral:
4 + th = 4th
You don’t need to insert the r from “fourth” into the numerical abbreviation.
So whenever you’re tempted to write 4rth, remember:
Four → fourth → 4th
It’s that simple.
Common Mistakes With 4th
Here are some mistakes worth avoiding:
4rth
Incorrect ordinal abbreviation.
4thth
The th ending is already included, so don’t repeat it.
4Th
In ordinary writing, the abbreviation is normally written 4th, with a lowercase t and h.
4th
This is the standard numerical abbreviation.
Fourth
This is the fully spelled-out form.
Frequently Asked Questions About 4rth or 4th
Is it 4rth or 4th?
4th is correct. “4rth” is an incorrect abbreviation of “fourth.”
What is correct, 4rth or 4th?
The correct form is 4th. It is the standard abbreviation for the ordinal word fourth.
Is 4rth or 4th floor correct?
4th floor is correct. You can also write fourth floor.
Is it 4rth or 4th year?
Use 4th year or fourth year. “4rth year” is incorrect.
Is it 4rth or 4th anniversary?
The correct phrase is 4th anniversary or fourth anniversary.
What does 4th mean?
4th means “fourth.” It describes the fourth position in an ordered sequence.
Why isn’t 4rth correct?
Although the word fourth contains an “r,” its standard numerical abbreviation is 4th. The abbreviation isn’t created by adding every letter from the full word.
Should I write 4th or fourth?
Both are correct. Use 4th when a numerical abbreviation is suitable and fourth when spelling out the ordinal is more appropriate for your style or context.
Is 4th grammatically correct?
Yes. 4th is a standard abbreviation for the ordinal number fourth.
Final Verdict: 4rth or 4th?
So, is it 4rth or 4th? The answer is clear: 4th is correct.
The full word is fourth, while its standard numerical abbreviation is 4th. Whether you’re talking about a 4th floor, 4th year, 4th anniversary, 4th place, or another sequence, use 4th rather than 4rth.
If you want to avoid abbreviations altogether, simply write fourth. Either way, the important thing is to leave 4rth behind—it isn’t the standard form.
