Many people search for “13rd or 13th” because English ordinal numbers can feel confusing. You see dates in emails, schoolwork, legal papers, or social posts, and suddenly you stop and think: Is it 13th or 13rd? That moment of doubt is very common, especially for learners of English and even native speakers who do not use ordinal numbers every day.
The confusion usually comes from patterns. We know 1st, 2nd, and 3rd, so it feels logical to write 13rd. But English does not always follow simple patterns. Some numbers break the rule, and 13 is one of them. Because writing dates correctly matters in exams, work emails, contracts, and online content, people want a clear and fast answer.
This 2026 guide solves the confusion once and for all. You will get a quick answer, the rule behind it, British vs American usage, common mistakes, and real-life examples. By the end, you will know exactly which form to use and why it is always correct. Explore the “full word comparison library” to spot similar mix-ups.
13rd or 13th – Quick Answer
The correct form is 13th. “13rd” is incorrect and should never be used.
Examples:
- ✅ 13th March
- ❌ 13rd March
- ✅ My birthday is on the 13th
- ❌ My birthday is on the 13rd
In English, ordinal numbers ending in 11, 12, and 13 always use “th”, not st, nd, or rd.
Why Is It 13th and Not 13rd? (Simple Rule)
Even though the number 13 ends with 3, it does not follow the same pattern as 3rd. This is because English has a special exception rule for 11, 12, and 13.
The rule you must remember:
- 11 → 11th
- 12 → 12th
- 13 → 13th
So the correct ordinal spelling is always 13th, and 13rd is never correct in any type of English writing.
The Origin of “13rd or 13th” Confusion
Ordinal numbers come from older English and Latin-based counting systems. Over time, English developed special endings for numbers that show position or order, such as first, second, and third.
While:
- 1 → 1st
- 2 → 2nd
- 3 → 3rd
The numbers 11, 12, and 13 are exceptions. They come from older word forms like eleventh, twelfth, and thirteenth. Because of this history, the “th” ending stayed fixed.
That is why spelling differences do not apply here. The rule is historical, not stylistic. So 13rd never existed as a correct form in standard English.
British English vs American English Spelling (2026 Update)
There is no difference between British and American English for this case. Both follow the same rule for ordinal numbers.
Comparison Table
| Number | British English | American English | Correct Form |
|---|---|---|---|
| 1 | 1st | 1st | 1st |
| 2 | 2nd | 2nd | 2nd |
| 3 | 3rd | 3rd | 3rd |
| 11 | 11th | 11th | 11th |
| 12 | 12th | 12th | 12th |
| 13 | 13th | 13th | 13th |
Which Spelling Should You Use?
You should always use 13th, no matter who your audience is:
- US audience → 13th
- UK audience → 13th
- Australia, Canada, India → 13th
- Global or international writing → 13th
There is no context, region, or style guide where 13rd is acceptable. Explore our “Grammar Mistakes” category for related writing errors.
Common Mistakes with 13rd or 13th
Here are frequent errors people make:
- ❌ Writing 13rd by copying the pattern of 3rd
- ❌ Mixing spoken and written English
- ❌ Assuming spelling rules change by country
Corrected Versions:
- ❌ The event is on 13rd June
✅ The event is on 13th June - ❌ He finished 13rd in the race
✅ He finished 13th in the race
13rd or 13th in Dates (Most Common Use)
Most people search “13rd or 13th” when writing a date. Here are the correct ways to write it:
✅ Correct date formats:
- 13th March
- March 13th
- the 13th of March
- on the 13th
❌ Wrong date formats:
- 13rd March
- March 13rd
- the 13rd of March
If you are writing for exams, office emails, legal documents, or official forms, always use 13th.
13rd or 13th in Everyday Examples (2026)
Emails
- ✅ Your appointment is scheduled for the 13th of April.
News
- ✅ The law was passed on the 13th of August.
Social Media
- ✅ Can’t wait for the 13th! Big day ahead.
Formal Writing
- ✅ The report was submitted on the 13th day of the month.
13rd or 13th – Google Trends & Usage Data
Search interest for “13rd or 13th” is high in countries where English is a second language. Many users search it while writing exams, filling forms, or creating online content.
In English-speaking countries, the correct form 13th appears in almost all published content. The incorrect form 13rd mostly appears in searches, not in professional writing. This shows people are checking before they make a mistake, which is a good habit. You might also like our “ccd or cc’d explanation” for a similar issue.
Comparison Table: Keyword Variations
| Variation | Correct | Usage |
| 13rd | ❌ No | Never correct |
| 13th | ✅ Yes | Always correct |
| Thirteenth | ✅ Yes | Formal and written words |
FAQs (13rd or 13th – 2026)
1. Is 13rd ever correct?
No. 13rd is always wrong.
2. Why is it 13th and not 13rd?
Because numbers ending in 11, 12, and 13 always use “th” in English.
3. Do Americans and British people write it differently?
No. Both use 13th.
4. Is “thirteenth” better than “13th”?
Both are correct. “13th” is more common in daily writing.
5. Can I use 13rd in informal writing?
No. It is incorrect in all writing styles.
6. Does this rule apply to other numbers?
Yes. 11th, 12th, and 13th follow the same rule.
Conclusion
The confusion around 13rd or 13th is very common, but the rule is simple once you understand it. 13th is the only correct form, and 13rd is always wrong. This does not change with country, writing style, or context. The reason comes from the history of English ordinal numbers, where 11, 12, and 13 are fixed exceptions. For another quick check, read “sitted or seated” next.
If you remember just one thing, remember this: numbers ending in 11, 12, and 13 always use “th”. That single rule will help you avoid mistakes in emails, exams, contracts, and online content. Using the correct form also makes your writing look professional and trustworthy.
Whenever you feel unsure, pause and choose 13th with confidence. English may have many tricky rules, but this one is clear and reliable.
D.H. Lawrence is a research-oriented writer focused on word comparison and semantic clarity within digital content. His work is grounded in close reading, source-based verification, and contextual language analysis, with an emphasis on how meaning shifts across usage, register, and intent. Drawing on editorial research practices, he examines words through their definitions, grammatical function, historical development, and contemporary application.
His approach is methodical rather than interpretive, aiming to present distinctions between similar terms in a way that is accurate, neutral, and easy to apply. By comparing words within real sentences and documented usage patterns, he helps readers avoid ambiguity and misinterpretation in both written and spoken language.
D.H. Lawrence writes for readers who rely on precision—students, writers, editors, and professionals—by offering content that prioritizes trust, clarity, and usefulness. Each article is structured to align with search intent while remaining informative beyond rankings, reflecting a consistent commitment to factual accuracy and reader understanding.
