Have you ever seen 13rd written somewhere and wondered if it was correct? Ordinal numbers can be confusing, especially when different endings like -st, -nd, -rd, and -th come into play. Many writers accidentally use the wrong suffix, leading to common grammar mistakes.
If you’re comparing 13rd vs 13th, the answer is straightforward: 13th is the correct form, while 13rd is grammatically incorrect.
In this guide, you’ll learn why 13th is correct, the rules for ordinal numbers, examples of proper usage, common mistakes to avoid, and easy tricks to remember the right form.
Quick Answer
13th is the correct ordinal form of the number 13.
13rd is incorrect and should never be used in standard English writing.
Examples:
- Today is the 13th of June. ✅
- Today is the 13rd of June. ❌
The ordinal number for 13 always takes the suffix -th.
What Does 13th Mean?
13th is the ordinal form of the number 13.
Ordinal numbers show position, order, rank, sequence, or placement.
Examples:
- The 13th chapter
- The 13th floor
- The 13th day of the month
- The 13th contestant
Unlike cardinal numbers (1, 2, 3, 13), ordinal numbers indicate order (1st, 2nd, 3rd, 13th).
What Does 13rd Mean?
13rd is not a correct English ordinal number.
It is usually the result of applying the wrong ordinal suffix to the number 13.
Incorrect examples:
- The 13rd student arrived late.
- My birthday falls on the 13rd.
Both examples should use 13th instead.
13rd vs 13th: What’s the Difference?
The difference is simple:
- 13th = Correct ordinal form
- 13rd = Incorrect ordinal form
Comparison Table: 13rd vs 13th
| Feature | 13rd | 13th |
|---|---|---|
| Grammatically Correct | No | Yes |
| Standard English Usage | No | Yes |
| Ordinal Number Form | Incorrect | Correct |
| Used in Dates | No | Yes |
| Used in Rankings | No | Yes |
| Example | 13rd place ❌ | 13th place ✅ |
Whenever you’re referring to the number 13 in an ordinal sense, use 13th.
Why Is 13th Correct?
English ordinal numbers follow specific suffix rules.
Basic Ordinal Endings
| Number | Ordinal |
|---|---|
| 1 | 1st |
| 2 | 2nd |
| 3 | 3rd |
| 4 | 4th |
| 5 | 5th |
| 6 | 6th |
| 7 | 7th |
| 8 | 8th |
| 9 | 9th |
| 10 | 10th |
Many people assume that because 13 ends in the digit 3, it should become 13rd.
However, that’s not how the rule works.
The Exception for 11, 12, and 13
The numbers 11, 12, and 13 always take -th endings.
Examples:
- 11th ✅
- 12th ✅
- 13th ✅
Not:
- 11st ❌
- 12nd ❌
- 13rd ❌
This exception exists because English treats these numbers as special cases.
Ordinal Number Rules Explained
To choose the correct suffix, look at the entire number, not just the last digit.
Use -st
Numbers ending in 1, except 11.
Examples:
- 1st
- 21st
- 31st
- 101st
But:
- 11th ❌ not 11st
Use -nd
Numbers ending in 2, except 12.
Examples:
- 2nd
- 22nd
- 32nd
But:
- 12th ❌ not 12nd
Use -rd
Numbers ending in 3, except 13.
Examples:
- 3rd
- 23rd
- 33rd
But:
- 13th ❌ not 13rd
Use -th
All other numbers.
Examples:
- 4th
- 8th
- 10th
- 13th
- 20th
- 100th
American vs British English
There is no difference between American and British English regarding 13th.
American English
Correct:
- July 13th
Incorrect:
- July 13rd
British English
Correct:
- 13th July
Incorrect:
- 13rd July
Both varieties of English follow the same ordinal number rules.
Common Uses of 13th
Dates
Examples:
- My appointment is on the 13th.
- The event takes place on August 13th.
- We leave on the 13th of next month.
Rankings
Examples:
- She finished in 13th place.
- The team ranked 13th overall.
Chapters and Sections
Examples:
- Read the 13th chapter.
- The answer appears in the 13th section.
Anniversaries and Events
Examples:
- The company celebrated its 13th anniversary.
- This is the 13th annual conference.
Common Mistakes to Avoid
Writing 13rd Because the Number Ends in 3
Incorrect:
- 13rd
Correct:
- 13th
Remember that 13 is an exception.
Confusing 13th with 23rd
Correct:
- 13th
- 23rd
The rules differ because only numbers ending in 13 take the exception.
Using the Wrong Date Format
Incorrect:
- June 13rd
Correct:
- June 13th
Always double-check ordinal endings in dates.
Examples of 13th in Sentences
Date Examples
- The meeting is scheduled for the 13th.
- Her birthday falls on the 13th of September.
- We arrived on the 13th.
Ranking Examples
- He finished 13th in the competition.
- The athlete secured 13th place.
Academic Examples
- Turn to the 13th page.
- The answer appears in the 13th chapter.
Business Examples
- This marks our 13th year in operation.
- The company held its 13th annual meeting.
Similar Ordinal Number Confusions
Many writers make mistakes with these numbers:
| Incorrect | Correct |
|---|---|
| 11st | 11th |
| 12nd | 12th |
| 13rd | 13th |
| 21th | 21st |
| 22th | 22nd |
| 23th | 23rd |
Learning these patterns helps prevent common grammar errors.
How to Remember the Difference
A simple trick is:
11, 12, and 13 are special. They always end in -th.
Think:
- 11th
- 12th
- 13th
No exceptions.
If the number ends in 11, 12, or 13, use -th, regardless of the final digit.
FAQs
Is 13rd correct?
No. 13rd is grammatically incorrect in standard English.
What is the correct ordinal form of 13?
The correct ordinal form is 13th.
Why isn’t it 13rd?
Because the numbers 11, 12, and 13 are special exceptions that always use -th endings.
Is 13th used in both American and British English?
Yes. Both American and British English use 13th.
How do I write the date correctly?
Examples:
- June 13th
- 13th June
Both are correct depending on style preference.
Is 23rd correct?
Yes. 23rd is correct because it does not end in 13.
What suffix does 13 take?
The number 13 always takes the suffix -th.
What are the exceptions to ordinal number rules?
The numbers ending in 11, 12, and 13 always use -th rather than -st, -nd, or -rd.
Summary
When comparing 13rd vs 13th, only 13th is correct. Although the number 13 ends in the digit 3, English grammar treats 11, 12, and 13 as special exceptions that always take the suffix -th. As a result, forms like 13rd, 11st, and 12nd are incorrect.
Whether you’re writing dates, rankings, anniversaries, chapter numbers, or formal documents, using 13th ensures grammatical accuracy and professionalism. Understanding the ordinal number rules will help you avoid one of the most common numbering mistakes in English.
Actionable Takeaway
Remember this simple rule: 11, 12, and 13 always end in -th. Whenever you’re writing the ordinal form of 13, use 13th and never 13rd. A quick proofreading check can prevent this common grammar error.
Shan Waston is a skilled writer at Symboliy.com, producing clear, engaging content on language, communication, and everyday expressions to help readers understand meaning and usage confidently in modern digital contexts.
