13rd vs 13th What’s Correct? Easy Guide to Avoid This Common Mistake

Have you ever seen 13rd written somewhere and wondered if it’s correct or just a typo? You’re not alone. Many people get confused when writing ordinal numbers, especially when numbers end in 3.

This small mistake is very common in English writing, but once you understand the rule, it becomes very easy to avoid.

In this guide, we’ll clearly explain 13rd vs 13th, what each means, which one is correct, and how to remember the rule forever. We’ll also include examples, common mistakes, a comparison table, and FAQs so you never get confused again.

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Quick Answer

The correct form is 13th.
13rd is incorrect and should never be used.
The number 13 always takes “th” because numbers ending in 11, 12, and 13 always use th, not st, nd, or rd.

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What Do 13rd and 13th Mean?

Ordinal numbers are numbers that show position or order (like 1st, 2nd, 3rd, 4th, etc.).

• 13th = Correct ordinal form of the number 13
• 13rd = Incorrect spelling and grammatical mistake

We use 13th when talking about order, dates, positions, floors, anniversaries, and rankings.

Examples:

• My exam is on the 13th.
• She finished in 13th place.
• His birthday is June 13th.
• This is the 13th chapter of the book.

Why 13rd Is Incorrect

Many people think that because 3 becomes 3rd, then 13 should become 13rd, but English grammar has a special rule.

Here is the rule:

Number	Correct Ordinal
1	1st
2	2nd
3	3rd
4	4th
11	11th
12	12th
13	13th

Important Rule:
Numbers ending in 11, 12, and 13 always use “th” — not st, nd, or rd.

So:

• 11th ✅
• 12th ✅
• 13th ✅
• 13rd ❌

Examples of 13th in Sentences

Here are real-life examples to help you understand how to use 13th correctly:

• The meeting is on the 13th of March.
• He came 13th in the race.
• We live on the 13th floor.
• Today is my 13th birthday.
• This is the 13th time I told you.

These examples show how ordinal numbers are used in daily English writing and speaking.

Common Mistakes People Make

Here are some common mistakes related to 13rd vs 13th:

• Writing 13rd instead of 13th
• Writing 13th as 13rd in dates
• Confusing ordinal rules for numbers ending in 3
• Thinking all numbers ending in 3 use rd

Wrong vs Correct Examples

Wrong	Correct
13rd birthday	13th birthday
March 13rd	March 13th
He finished 13rd	He finished 13th
13rd floor	13th floor

Easy Trick to Remember the Rule

Here is a simple memory trick:

“1, 2, 3 follow special rules… but 11, 12, 13 break the rules.”

So remember:

• 1st, 2nd, 3rd
• BUT → 11th, 12th, 13th

This trick helps you remember forever.

American vs British English

Good news — there is no difference between American and British English for this rule.

Both use:

• 13th ✅
• 13rd ❌

The only small difference is in date writing format:

American English	British English
March 13th	13th March
03/13/2025	13/03/2025

But 13th spelling stays the same in both.

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Related Ordinal Number Rules

Here are more ordinal number examples to help you understand the pattern:

Number	Ordinal
3	3rd
4	4th
10	10th
11	11th
12	12th
13	13th
21	21st
22	22nd
23	23rd
24	24th

Notice:

• 21st
• 22nd
• 23rd
• 24th
  But:
• 11th
• 12th
• 13th (special case)

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FAQs

1. Is 13rd ever correct?

No, 13rd is never correct in English. The correct form is always 13th.

2. Why is it 13th and not 13rd?

Because numbers ending in 11, 12, and 13 always use “th” due to English grammar rules.

3. Do all numbers ending in 3 use “rd”?

No. Only numbers like 3, 23, 33, 43 use rd. But 13 is an exception → 13th.

4. How do you write 13th in words?

13th = Thirteenth

5. Is it March 13 or March 13th?

Both are correct, but:

• Formal writing: March 13
• Informal writing: March 13th

6. What is the rule for st, nd, rd, th?

• 1 → st
• 2 → nd
• 3 → rd
• 4–20 → th
• Exception → 11, 12, 13 always th

7. How can I remember ordinal numbers easily?

Remember this pattern:
1st, 2nd, 3rd, 4th… 11th, 12th, 13th… 21st, 22nd, 23rd

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Summary

Understanding the difference between 13rd vs 13th is very important for correct English writing. The correct form is 13th, and 13rd is always wrong. This happens because numbers ending in 11, 12, and 13 are special cases and always use “th”.

If you are writing dates, positions, birthdays, floors, or rankings, you should always use 13th. This rule is the same in both American and British English, so you don’t need to worry about regional differences.

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Actionable Takeaway

Here’s a simple rule you can remember:

• 1st, 2nd, 3rd
• 11th, 12th, 13th (special rule)
• 21st, 22nd, 23rd

If the number ends in 13 → Always use “th”.

Once you remember this rule, you’ll never write 13rd again.