Have you ever seen 13rd written somewhere and wondered if it was correct? Ordinal numbers in English can sometimes be confusing, especially when different endings like st, nd, rd, and th are involved. Many learners and even native speakers occasionally make mistakes when writing dates, rankings, or numbered items.
If you’re searching for the difference between 13rd vs 13th, the good news is that the answer is straightforward. Understanding the correct form will help you write more accurately in emails, academic work, business documents, and everyday communication.
Quick Answer
13th is the correct form.
❌ 13rd — Incorrect
✅ 13th — Correct
Examples:
- My birthday is on the 13th of June.
- She finished in 13th place.
- The meeting will be held on the 13th floor.
The ordinal number for 13 always uses th, making 13th the only correct spelling.
What Do 13rd and 13th Mean?
Both forms are intended to represent the ordinal version of the number 13, but only one follows English grammar rules.
13th
13th is the correct ordinal number form of 13.
Ordinal numbers show:
- Position
- Order
- Rank
- Sequence
Examples:
- The 13th chapter
- The 13th student
- The 13th anniversary
- The 13th day of the month
13rd
13rd is a grammatical mistake.
People sometimes assume that because 3 uses rd (as in 3rd), then 13 should also become 13rd. However, English ordinal number rules do not work that way.
Why Is 13th Correct?
English ordinal numbers generally follow these endings:
| Number | Correct Ordinal |
|---|---|
| 1 | 1st |
| 2 | 2nd |
| 3 | 3rd |
| 4 | 4th |
| 5 | 5th |
| 6 | 6th |
| 7 | 7th |
| 8 | 8th |
| 9 | 9th |
| 10 | 10th |
However, there is a special rule for numbers ending in 11, 12, and 13.
These numbers always take th:
| Number | Correct Form |
| 11 | 11th |
| 12 | 12th |
| 13 | 13th |
Therefore:
- ❌ 11st
- ❌ 12nd
- ❌ 13rd
Instead:
- ✅ 11th
- ✅ 12th
- ✅ 13th
The Rule Behind Ordinal Numbers
The ending of an ordinal number usually depends on the last digit.
Use “st”
For numbers ending in 1:
- 1st
- 21st
- 31st
- 101st
Exception:
- 11th
Use “nd”
For numbers ending in 2:
- 2nd
- 22nd
- 32nd
Exception:
- 12th
Use “rd”
For numbers ending in 3:
- 3rd
- 23rd
- 33rd
Exception:
- 13th
Use “th”
For most other numbers:
- 4th
- 5th
- 14th
- 20th
- 100th
This is why 13th is correct and 13rd is incorrect.
13rd vs 13th Comparison Table
| Feature | 13rd | 13th |
| English Grammar | Incorrect | Correct |
| Standard Usage | No | Yes |
| Accepted in Writing | No | Yes |
| Used in Dates | No | Yes |
| Used in Rankings | No | Yes |
| Dictionary Approved | No | Yes |
| Professional Writing | No | Yes |
Examples of 13th in Sentences
Here are some natural examples using the correct form.
Dates
- The event will take place on the 13th of August.
- We arrived on the 13th day of the month.
- Her birthday falls on the 13th.
Rankings
- He finished 13th in the competition.
- Our team ended the season in 13th place.
- She secured the 13th position.
Sequence
- This is the 13th chapter of the book.
- The 13th applicant received the scholarship.
- The 13th participant entered the room.
Common Mistakes People Make
Mistake 1: Following the Last Digit Only
Many people see the digit 3 and automatically choose rd.
Incorrect:
- 13rd
- 113rd
Correct:
- 13th
- 113th
Because numbers ending in 13 are exceptions.
Mistake 2: Applying 3rd Rules Everywhere
People know:
- 3rd
- 23rd
- 33rd
Then they incorrectly write:
- 13rd
But 13 belongs to the special group:
- 11th
- 12th
- 13th
Mistake 3: Writing Dates Incorrectly
Incorrect:
- June 13rd
- March 13rd
Correct:
- June 13th
- March 13th
When Should You Use 13th?
Use 13th whenever you’re referring to the ordinal form of the number 13.
Common situations include:
- Dates
- Birthdays
- Anniversaries
- Rankings
- Floors in buildings
- Chapters in books
- Sequential lists
Examples:
- The office is on the 13th floor.
- Today is the 13th day of the month.
- He was the 13th person selected.
Is 13rd Ever Correct?
No.
There are no standard English situations where 13rd is considered correct.
Whether you’re writing:
- Academic papers
- Business reports
- Social media posts
- Emails
- Books
- Articles
The correct form remains:
✅ 13th
The form 13rd is simply an error.
American vs British English
One interesting fact is that there is no difference between American and British English regarding this rule.
Both varieties use:
- 13th
Both reject:
- 13rd
Examples:
American English
- July 13th is my birthday.
British English
- The meeting is on the 13th of July.
The date format may differ, but the ordinal number remains exactly the same.
Related Ordinal Numbers
Understanding nearby numbers can help reinforce the rule.
| Number | Correct Ordinal |
| 11 | 11th |
| 12 | 12th |
| 13 | 13th |
| 14 | 14th |
| 21 | 21st |
| 22 | 22nd |
| 23 | 23rd |
| 24 | 24th |
Notice that 23rd uses rd, but 13th uses th because of the special exception.
Memory Trick to Remember
A simple trick is:
11, 12, and 13 always use “th.”
Remember this phrase:
“The teen exceptions are 11th, 12th, and 13th.”
Whenever you see 13, automatically choose th, not rd.
Frequently Asked Questions
Is 13rd grammatically correct?
No. 13rd is not grammatically correct in standard English.
Why is it 13th instead of 13rd?
Because numbers ending in 11, 12, and 13 are exceptions and always use th.
How do you write the ordinal form of 13?
The correct ordinal form is 13th.
Is June 13rd correct?
No. The correct date format is June 13th.
Is 113rd correct?
No. Since the number ends in 13, the correct form is 113th.
Do Americans use 13th?
Yes. American English uses 13th.
Do British people use 13th?
Yes. British English also uses 13th.
What is the easiest way to remember the rule?
Remember that 11th, 12th, and 13th are special exceptions that always take th.
Summary
The debate over 13rd vs 13th has a clear answer: 13th is the only correct form in English. The form 13rd is a common mistake that occurs when people incorrectly apply the rd ending from 3rd to the number 13. English grammar treats 11, 12, and 13 as special exceptions, so they always use th.
Whether you’re writing dates, rankings, anniversaries, addresses, or numbered items, you should always choose 13th. Using the correct ordinal form improves clarity, professionalism, and grammatical accuracy in every type of writing.
Actionable Takeaway
Whenever you write the number 13 in ordinal form, use 13th and never 13rd. A quick memory aid is to remember that 11th, 12th, and 13th always end in “th.” Keeping this rule in mind will help you avoid one of the most common ordinal-number mistakes in English.
Featured Image Prompt: Create a clean, modern educational typography graphic. Split the image into two distinct rectangular frames. The left frame displays the word “13rd” in bold English typography with a red incorrect mark. The right frame displays “13th” in bold English typography with a green correct mark. Place a large stylish “VS” between the two frames. White background, professional grammar-learning theme, high readability, SEO blog featured image design, modern typography, crisp text, educational comparison layout.
Bret Lee writes educational and research-based content for Whygenix.com, focused on clarity, accuracy, and explaining why concepts matter through simple, engaging, reader-friendly writing.
