33rd or 33th — which spelling is correct? The correct form is 33rd, while 33th is incorrect in standard English. The number 33 becomes thirty-third when written as an ordinal number, so it takes the suffix -rd, not -th. This rule applies to phrases such as 33rd birthday, 33rd anniversary, and 33rd place.
Understanding the difference between 33rd and 33th also helps you avoid similar mistakes with ordinal numbers such as 13th, 23rd, and 34th. You can use these forms in dates, invitations, rankings, business milestones, and social media captions. Once you understand how ordinal suffixes work, choosing the correct spelling becomes much easier.
Is It 33rd or 33th?
33rd is the correct spelling, and 33th is incorrect. The ordinal form of 33 is thirty-third, which explains why the number uses the suffix -rd. Use 33rd when describing a position, sequence, birthday, anniversary, or other milestone. For example, write “She celebrated her 33rd birthday,” not “She celebrated her 33th birthday.”
Why 33rd Is the Correct Spelling
The number 33 is a cardinal number, which expresses a quantity. When you use it to indicate an order or position, it becomes an ordinal number.
For example:
- 33: Thirty-three books are on the shelf.
- 33rd: She picked up the 33rd book.
- 33rd: Today is his 33rd birthday.
- 33rd: Our company celebrated its 33rd anniversary.
The word thirty-three becomes thirty-third in its ordinal form. The spelling of the final word determines the suffix used in the numerical form.
Here is the connection:
| Cardinal number | Ordinal number | Written form |
| 1 | 1st | First |
| 2 | 2nd | Second |
| 3 | 3rd | Third |
| 13 | 13th | Thirteenth |
| 23 | 23rd | Twenty-third |
| 33 | 33rd | Thirty-third |
| 43 | 43rd | Forty-third |
| 53 | 53rd | Fifty-third |
Notice that 33rd follows the same pattern as 3rd and 23rd. The final digit is 3, so the number normally takes -rd, provided the number does not end in 13.
Why 33th Is Incorrect
The spelling 33th results from applying the common -th ending to a number that follows a different pattern.
Many ordinal numbers do use -th. Examples include 4th, 6th, 10th, and 30th. However, the suffix depends on the number’s final digits, not simply on the fact that it represents an ordinal position.
Compare these examples:
- Incorrect: My brother is celebrating his 33th birthday.
- Correct: My brother is celebrating his 33rd birthday.
- Incorrect: This is the 33th anniversary of the organization.
- Correct: This is the 33rd anniversary of the organization.
- Incorrect: She finished in 33th place.
- Correct: She finished in 33rd place.
The incorrect form may appear in online searches, informal messages, or unedited content. However, it is not the standard spelling and should not appear in polished writing.
33rd vs. 33th at a Glance
| Form | Correct or incorrect? | Explanation |
| 33rd | Correct | Standard ordinal form of 33 |
| 33th | Incorrect | Uses the wrong ordinal suffix |
| Thirty-three | Correct | Written cardinal number |
| Thirty-third | Correct | Written ordinal number |
| Thirty-threeth | Incorrect | Not the standard written form |
Quick rule: If you mean the ordinal form of thirty-three, write 33rd or spell it out as thirty-third.
What Does 33rd Mean?
33rd means thirty-third in a sequence or order. It identifies the person, item, event, or position that comes after the thirty-second and before the thirty-fourth. Unlike 33, which expresses a quantity, 33rd identifies an ordinal position. You might see it in rankings, dates, birthdays, anniversaries, numbered lists, and other situations involving order.
33rd Meaning in Simple English
The simplest way to understand 33rd is to think of it as the position that comes after 32nd.
Imagine 40 runners competing in a race. The runner who finishes after the thirty-second runner and before the thirty-fourth runner finishes in 33rd place.
The number does not tell you how many runners participated. Instead, it tells you the position of one runner within the results.
The same principle applies to other situations:
- In a queue: The 33rd person is the thirty-third person in line.
- In a book: Chapter 33 is the thirty-third chapter, while the 33rd chapter identifies its position.
- In a birthday: A 33rd birthday marks the thirty-third anniversary of someone’s birth.
- In a business: A company’s 33rd anniversary marks 33 years since the relevant founding date.
- In a competition: The 33rd-place participant ranks after the 32nd-place participant.
The meaning stays the same across these contexts. The number indicates order rather than quantity.
Examples of 33rd in Sentences
Here are original examples showing how to use 33rd correctly.
Everyday situations
- My sister will celebrate her 33rd birthday in December.
- He lives on the 33rd floor of the apartment building.
- The 33rd student entered the classroom just before the bell rang.
- I found the answer in the 33rd paragraph of the report.
Work and education
- The university welcomed its 33rd graduating class.
- Our team finished in 33rd place in the national competition.
- The company opened its 33rd store in the region.
- The researcher discussed the results in the 33rd section of the paper.
Dates and milestones
- The organization marked its 33rd anniversary this year.
- She received the award during the event’s 33rd edition.
- The family gathered to celebrate their parents’ 33rd wedding anniversary.
Each example uses 33rd to identify a position, occurrence, or milestone in a sequence.
What Does 33th Mean?
33th is generally a misspelling of 33rd. In standard English, it does not serve as the accepted ordinal form of 33. If you encounter it in a birthday message, anniversary announcement, or online post, the intended meaning is usually thirty-third.
For example, someone searching for “33th meaning” probably wants to understand the correct spelling or determine whether the form is acceptable.
The correction depends on the context:
- “Happy 33th birthday!” becomes “Happy 33rd birthday!”
- “The 33th anniversary” becomes “The 33rd anniversary.”
- “He finished 33th” becomes “He finished 33rd.”
You generally do not need to explain the spelling error when correcting an ordinary message. Replace the incorrect form with 33rd and keep the original meaning.
How Do You Write 33rd in Words?
The correct written form of 33rd is thirty-third. Use thirty-three when expressing the number as a quantity and thirty-third when expressing a position or order. For example, “I bought thirty-three tickets” describes a quantity, while “She won her thirty-third match” identifies an ordinal occurrence.
33rd in Words: Thirty-Third
The written form of an ordinal number often differs slightly from its cardinal form.
For 33, the distinction is straightforward:
| Purpose | Numeric form | Written form |
| Quantity | 33 | Thirty-three |
| Ordinal position | 33rd | Thirty-third |
| Quantity in a sentence | 33 items | Thirty-three items |
| Ordinal in a sentence | 33rd item | Thirty-third item |
The hyphen in thirty-third joins the tens word and the ordinal unit. Standard English generally uses hyphens in compound numbers from twenty-one through ninety-nine when writing them as words.
Consider these examples:
- Cardinal: The library received thirty-three new books.
- Ordinal: This is the thirty-third book in the collection.
- Cardinal: The business employs thirty-three people.
- Ordinal: This is the company’s thirty-third year in operation.
The distinction matters because changing the number’s form changes its grammatical function.
How to Use 33rd in Dates and Rankings
Ordinal numbers appear in many types of writing, but their formatting can vary by style and context.
In rankings, use 33rd to identify a position.
Example: “The athlete finished 33rd in the regional championship.”
In birthdays, use 33rd to mark a person’s age milestone.
Example: “We’re organizing a surprise party for his 33rd birthday.”
In anniversaries, use 33rd to identify the number of years or the corresponding anniversary.
Example: “The couple celebrated their 33rd wedding anniversary.”
In dates, ordinal formatting depends on the style convention.
For example:
- “October 23” is common in American date writing.
- “October 23rd” is also used informally, especially in invitations and personal messages.
- “The twenty-third of October” is a written-out form used in certain contexts.
American formal prose often uses cardinal numbers in full dates without ordinal suffixes. However, ordinal forms remain natural in phrases such as “the 23rd day of October.”
When writing a formal report, follow the publication’s style guide. For a birthday invitation or social media caption, choose the form that best fits the tone while keeping the suffix correct.
The Ordinal Suffix Rule for Numbers Ending in 3
Most ordinal numbers follow a predictable suffix pattern:
- Numbers ending in 1 generally take -st.
- Numbers ending in 2 generally take -nd.
- Numbers ending in 3 generally take -rd.
- Most other numbers take -th.
However, there is one important exception: numbers ending in 11, 12, or 13 use -th.
This explains the difference between 13th and 33rd.
| Number | Correct ordinal | Reason |
| 1 | 1st | Ends in 1 |
| 2 | 2nd | Ends in 2 |
| 3 | 3rd | Ends in 3 |
| 11 | 11th | Special exception |
| 12 | 12th | Special exception |
| 13 | 13th | Special exception |
| 21 | 21st | Ends in 1, not 11 |
| 22 | 22nd | Ends in 2, not 12 |
| 23 | 23rd | Ends in 3, not 13 |
| 31 | 31st | Ends in 1, not 11 |
| 32 | 32nd | Ends in 2, not 12 |
| 33 | 33rd | Ends in 3, not 13 |
The key is to check the final two digits first. If they are 11, 12, or 13, use -th. Otherwise, the final digit usually determines the suffix.
This small check prevents mistakes such as writing 13rd or 33th.
How Do You Pronounce 33rd?
You pronounce 33rd as thirty-third. The phrase has two parts: thirty and third. The first part identifies the number of tens, while the second expresses its ordinal form. When speaking, pronounce both parts clearly and pay attention to the voiced “th” sound at the beginning of third.
33rd Pronunciation in American English
In American English, the phrase thirty-third is pronounced with the stress patterns commonly used for these two words.
A practical guide is:
33rd = thirty-third
The first word sounds like thirty, and the second sounds like third. The phrase contains two spoken words even though the written numeral uses a number and a suffix.
Here are a few examples in natural speech:
- “Today is my thirty-third birthday.”
- “She finished thirty-third in the competition.”
- “They celebrated their thirty-third anniversary.”
The pronunciation does not change simply because you write the number as 33rd rather than spelling it out.
How to Pronounce Thirty-Third Clearly
The word thirty-third can be challenging for English learners because it contains two different “th” sounds.
The first sound in thirty is typically unvoiced, like the sound at the beginning of think. The first sound in third is voiced, like the sound at the beginning of this.
To practice:
- Say “thirty” slowly. Place your tongue lightly between your teeth and let air pass for the initial sound.
- Say “third” slowly. Keep your tongue in a similar position, but add voice to the initial consonant.
- Join the words. Say thirty-third at a comfortable pace without dropping the final sounds.
- Use a full sentence. Practice saying, “This is my thirty-third birthday.”
You do not need to exaggerate the sounds in ordinary conversation. Clear articulation matters more than speaking slowly once you become comfortable with the phrase.
Is 33rd Pronounced Differently From 33th?
There is no standard ordinal pronunciation associated with the incorrect spelling 33th. The intended expression is normally thirty-third.
For example, if someone writes “Happy 33th birthday,” you should read the intended message as “Happy thirty-third birthday,” not invent a separate pronunciation for the typo.
Remember that ordinal suffixes represent established number forms. They are not arbitrary endings that you can attach to any number and pronounce independently.
Is It 33rd Birthday or 33th Birthday?
33rd birthday is the correct expression. A birthday marks the anniversary of the day someone was born, and the ordinal number identifies the age milestone. Because 33 is written as thirty-third in its ordinal form, the correct phrase is 33rd birthday. Use this spelling on cards, invitations, gifts, and social media posts.
The Correct Phrase Is 33rd Birthday
The phrase 33rd birthday follows the same spelling rule as other ordinal-number expressions.
Correct examples include:
- Happy 33rd birthday!
- Join us to celebrate Maya’s 33rd birthday.
- We’re planning a surprise party for his 33rd birthday.
- She shared a photo from her 33rd birthday celebration.
- The invitation reads, “Come celebrate my 33rd birthday with me!”
Avoid writing 33th birthday in edited or professional content.
One useful point: the expression refers to the birthday associated with turning 33, not the number of birthday parties someone has held. Although people celebrate birthdays annually, the ordinal refers to the age milestone.
How to Say Happy 33rd Birthday
A birthday message can be short, funny, heartfelt, or formal. The best choice depends on your relationship with the person.
Here are some original examples.
Short and simple
- Happy 33rd birthday! Wishing you a wonderful year ahead.
- Cheers to 33 years and many more happy memories.
- Happy birthday! May your 33rd year bring you plenty of reasons to smile.
Funny and playful
- Happy 33rd birthday! You’re officially 33 years of awesome.
- Thirty-three looks good on you. Keep making it count!
- Happy 33rd! May your cake be big and your responsibilities small today.
Heartfelt
- Happy 33rd birthday! I hope this year brings you peace, love, and exciting new opportunities.
- Wishing you a beautiful 33rd birthday filled with the people and moments that matter most.
- May your 33rd year bring you closer to your dreams and remind you how much you mean to others.
Formal or professional
- Wishing you a happy 33rd birthday and continued success in the year ahead.
- Happy 33rd birthday! May the coming year bring you happiness, good health, and new achievements.
- Best wishes on your 33rd birthday. I hope you enjoy a memorable celebration.
You can personalize any message by adding a name, a shared memory, or a specific wish for the year ahead.
33rd Birthday Captions for Social Media
If you’re posting a birthday photo, choose a caption that matches the mood of the picture.
Short 33rd birthday captions
- Hello, 33.
- Chapter 33 begins.
- Thirty-three and thriving.
- Making 33 count.
- A new year, a new chapter.
- Celebrating 33 years of life.
Funny 33rd birthday captions
- Level 33 unlocked.
- Officially 33, still figuring it out.
- Thirty-three candles and a whole lot of wishes.
- Aging like a classic, one year at a time.
- I’m 33. The cake is doing most of the heavy lifting.
- Thirty-three years of questionable decisions and excellent stories.
Confident 33rd birthday captions
- Thirty-three and becoming more myself every day.
- Walking into 33 with confidence and purpose.
- My 33rd year, my rules.
- Growing, learning, and glowing at 33.
- Thirty-three looks like progress.
Grateful 33rd birthday captions
- Grateful for 33 years of lessons, love, and memories.
- Entering my 33rd year with a full heart.
- Thirty-three years of life and countless reasons to be thankful.
- Celebrating the journey that brought me here.
- Here’s to the people, places, and moments that shaped my first 33 years.
Caption tip: You can use a phrase such as “Chapter 33 begins” when you want a short, stylish caption. If clarity matters more, use “Celebrating my 33rd birthday” so readers immediately understand the occasion.
Common Mistakes in 33rd Birthday Messages
Birthday messages often contain errors because people type quickly or copy a phrase without checking its spelling.
| Incorrect phrase | Correct phrase |
| Happy 33th birthday | Happy 33rd birthday |
| My 33th birthday party | My 33rd birthday party |
| Welcome to your 33th year | Welcome to your 33rd year |
| Celebrating 33th years | Celebrating 33 years |
| Happy thirty-threeth birthday | Happy thirty-third birthday |
Notice that the last two examples involve different mistakes. The expression “celebrating 33 years” uses a cardinal number and does not need an ordinal suffix. Meanwhile, “thirty-third birthday” uses the correct written ordinal form.
Is It 33rd Anniversary or 33th Anniversary?
33rd anniversary is correct, while 33th anniversary is incorrect. An anniversary marks the yearly recurrence of an event, and the ordinal identifies which occurrence or milestone you are celebrating. Use 33rd anniversary for wedding anniversaries, company milestones, organizational celebrations, and other events that have reached their thirty-third year.
The Correct Form Is 33rd Anniversary
The spelling rule for birthdays also applies to anniversaries. Both phrases use an ordinal number, so both require the standard form 33rd.
Correct examples:
- Our company celebrated its 33rd anniversary.
- They marked their 33rd wedding anniversary with a family dinner.
- The organization announced its 33rd anniversary celebration.
- The museum hosted a special event for its 33rd anniversary.
- We are preparing a campaign to celebrate the brand’s 33rd anniversary.
The word anniversary does not affect the ordinal suffix. The number remains 33rd regardless of the noun that follows it.
Examples of 33rd Anniversary Wishes
Choose a message that fits the relationship or occasion.
Wedding anniversary wishes
- Happy 33rd wedding anniversary! May your years together continue to bring love and happiness.
- Congratulations on 33 years of marriage, shared memories, and lasting commitment.
- Wishing you a beautiful 33rd anniversary filled with laughter and cherished moments.
Business anniversary messages
- Congratulations on your 33rd anniversary. Here’s to continued growth and future success.
- Celebrating 33 years of service, dedication, and strong relationships.
- Best wishes on reaching your company’s 33rd anniversary and beginning another chapter of success.
Organizational anniversary messages
- Congratulations on 33 years of meaningful work and community service.
- Wishing your organization continued progress as it celebrates its 33rd anniversary.
- Here’s to 33 years of achievements and the opportunities still ahead.
For formal writing, you can also spell out the number: “The organization celebrated its thirty-third anniversary.” Both 33rd anniversary and thirty-third anniversary are correct.
33rd vs. Other Common Ordinal-Number Mistakes
Comparing 33rd with other ordinal numbers makes the suffix rule easier to remember. The endings -st, -nd, -rd, and -th depend on the number’s final digits, with a special exception for 11, 12, and 13. This section explains why forms such as 34th and 13th are correct even though their endings differ.
34th or 34rd?
34th is correct; 34rd is incorrect. The number 34 is written as thirty-four, and its ordinal form is thirty-fourth. Because the number ends in 4, it takes the suffix -th rather than -rd.
Examples:
- Correct: She celebrated her 34th birthday.
- Incorrect: She celebrated her 34rd birthday.
- Correct: The team finished in 34th place.
- Correct: The company marked its 34th anniversary.
Compare 33 and 34:
| Number | Correct form | Written form |
| 32 | 32nd | Thirty-second |
| 33 | 33rd | Thirty-third |
| 34 | 34th | Thirty-fourth |
| 35 | 35th | Thirty-fifth |
The suffix changes because the final digit changes. A useful method is to say the number in words. If you know the correct written ordinal, you can usually identify the right numeric suffix.
13th or 13rd?
13th is correct; 13rd is incorrect. Although 13 ends in the digit 3, it belongs to the special group of numbers ending in 13. Ordinal numbers ending in 11, 12, or 13 use -th, so the correct form is thirteenth.
Examples:
- Correct: Today is the 13th of May.
- Incorrect: Today is the 13rd of May.
- Correct: She celebrated her 13th birthday.
- Correct: He finished 13th in the competition.
Why does 33rd use -rd while 13th uses -th?
The rule checks the final two digits before checking the final digit. The number 13 falls within the exception, but 33 does not.
Compare:
- 3rd — third
- 13th — thirteenth
- 23rd — twenty-third
- 33rd — thirty-third
- 43rd — forty-third
This exception explains many common spelling mistakes. People sometimes focus only on the last digit and assume that every number ending in 3 takes -rd. The final-two-digit check prevents that error.
33rd vs. 30th vs. 33
These three forms look similar, but they have different meanings.
| Form | Written form | Meaning | Example |
| 33 | Thirty-three | A quantity | I bought 33 tickets. |
| 30th | Thirtieth | An ordinal position or milestone | She celebrated her 30th birthday. |
| 33rd | Thirty-third | An ordinal position or milestone | He celebrated his 33rd birthday. |
Use 33 when you want to count something. Use 33rd when you want to identify its position or an event’s ordinal milestone.
For example:
- “The club has 33 members” means the club contains thirty-three people.
- “She was the 33rd member to join” identifies her position in the joining sequence.
- “The event’s 33rd edition takes place this year” identifies the thirty-third occurrence.
Similarly, 30th represents the ordinal form of 30, which is thirtieth. It does not replace 33rd because the numbers describe different positions.
Quick Reference Table for Ordinal Suffixes
Use this table when you need to check an ordinal number quickly.
| Number | Correct form | Written form |
| 1 | 1st | First |
| 2 | 2nd | Second |
| 3 | 3rd | Third |
| 4 | 4th | Fourth |
| 5 | 5th | Fifth |
| 10 | 10th | Tenth |
| 11 | 11th | Eleventh |
| 12 | 12th | Twelfth |
| 13 | 13th | Thirteenth |
| 20 | 20th | Twentieth |
| 21 | 21st | Twenty-first |
| 22 | 22nd | Twenty-second |
| 23 | 23rd | Twenty-third |
| 24 | 24th | Twenty-fourth |
| 30 | 30th | Thirtieth |
| 31 | 31st | Thirty-first |
| 32 | 32nd | Thirty-second |
| 33 | 33rd | Thirty-third |
| 34 | 34th | Thirty-fourth |
| 35 | 35th | Thirty-fifth |
| 40 | 40th | Fortieth |
| 43 | 43rd | Forty-third |
| 53 | 53rd | Fifty-third |
| 103 | 103rd | One hundred third |
The pattern becomes easier to see when you compare numbers within the same group.
For example, 31st, 32nd, and 33rd use different suffixes because their final digits are 1, 2, and 3. However, 11th, 12th, and 13th all use -th because they are exceptions.
Simple Tips to Remember Whether to Use 33rd or 33th
You do not need to memorize every ordinal number individually. A simple checking method will help you identify the correct suffix for 33rd and most other numbers.
Check the Final Two Digits First
Start by looking at the last two digits.
If the number ends in 11, 12, or 13, use -th.
Examples:
- 11th
- 12th
- 13th
- 111th
- 112th
- 113th
This rule applies even when the number contains hundreds or thousands. For example, 113th is correct, not 113rd.
Check the Final Digit
If the final two digits are not 11, 12, or 13, check the last digit.
- Ends in 1: use -st, as in 21st.
- Ends in 2: use -nd, as in 22nd.
- Ends in 3: use -rd, as in 33rd.
- Ends in 0, 4, 5, 6, 7, 8, or 9: use -th, as in 30th or 34th.
This method works for large numbers too. For instance, 203rd is correct because the number ends in 3 and its final two digits are not 13.
Say the Number in Words
When you are unsure, spell out the ordinal number.
For 33, the correct form is thirty-third. That written form confirms the numeric spelling: 33rd.
You can use the same approach with other numbers:
- 23rd = twenty-third
- 34th = thirty-fourth
- 43rd = forty-third
- 113th = one hundred thirteenth
Learning the written forms of common ordinal numbers reinforces the suffix patterns.
Proofread Milestones and Invitations
A small typo can stand out on a birthday invitation, anniversary card, or company announcement. Before publishing, check the ordinal number as well as the surrounding phrase.
For example:
Draft: “Join us to celebrate our 33th anniversary!”
Corrected version: “Join us to celebrate our 33rd anniversary!”
You can also use a word processor’s spelling checker, but do not rely on it alone. A tool may miss an incorrect number suffix, especially when the numeral and suffix appear together.
Frequently Asked Questions
Is It 33rd or 33th?
33rd is correct. The ordinal form of 33 is thirty-third, so the number takes the suffix -rd. The form 33th is a spelling mistake in standard English.
What Does 33th Mean?
33th is generally an incorrect spelling of 33rd. People usually use it when they want to refer to the thirty-third position, birthday, anniversary, or another milestone. The standard form is 33rd.
How Do You Write 33rd in Words?
Write 33rd as thirty-third. Use thirty-three for the cardinal number and thirty-third for the ordinal number. For example, “thirty-three students attended” expresses a quantity, while “the thirty-third student arrived” identifies a position.
How Do You Pronounce 33rd?
Pronounce 33rd as thirty-third. Say thirty followed by third. Pay attention to the initial “th” sound in third, which is voiced, unlike the unvoiced “th” at the start of thirty.
Is It Happy 33th Birthday or Happy 33rd Birthday?
The correct greeting is Happy 33rd Birthday! The suffix -rd matches the ordinal form thirty-third. You can also write “Happy thirty-third birthday!” when you prefer to spell out the number.
Is It 33rd or 33th Anniversary?
33rd anniversary is correct. The same ordinal rule applies to wedding anniversaries, company anniversaries, and other milestones. For example, write “The organization celebrated its 33rd anniversary,” not “The organization celebrated its 33th anniversary.”
Final Thoughts on 33rd or 33th
When choosing between 33rd or 33th, remember that 33rd is the only correct standard form. The number 33 becomes thirty-third when you use it as an ordinal, which explains why it takes -rd rather than -th.
This rule applies to everyday writing, dates, rankings, birthdays, anniversaries, and social media captions. It also becomes easier to remember when you compare 33rd with similar forms such as 23rd, 34th, and 13th.
Before you publish a birthday message or write about a milestone, check the final two digits and then the last digit. If you still have doubts, spell the number out as thirty-third.
The simple rule to remember: Write 33rd, say thirty-third, and avoid 33th in standard English.
