When you are writing a birthday card or planning a big celebration, getting the details right matters. If you are celebrating a milestone year, you might find yourself hesitating over how to write it down. Is it written as 22nd or 22th?
The correct spelling and abbreviation for the twenty-second birthday is 22nd. The form "22th" is a spelling mistake that breaks standard English ordinal number rules. Understanding how English forms these numbers makes it easy to remember why some endings change while others stay the same.
Understanding Ordinal Numbers
Cardinal numbers tell us how many items exist, such as one, two, or twenty-two. Ordinal numbers show position or order in a sequence, such as first, second, or twenty-second. When writing these numbers in digits, you attach a two-letter suffix to the end of the number.
The suffix you choose depends entirely on the final digit of the number. English uses four main ordinal suffixes:
- -st: Used for numbers ending in 1 (1st, 21st, 31st, 41st)
- -nd: Used for numbers ending in 2 (2nd, 22nd, 32nd, 42nd)
- -rd: Used for numbers ending in 3 (3rd, 23rd, 33rd, 43rd)
- -th: Used for numbers ending in 4, 5, 6, 7, 8, 9, and 0 (4th, 5th, 10th, 11th, 12th, 13th, 20th)
Because twenty-two ends in the digit two, it takes the -nd suffix. That is why you write 22nd. Writing "22th" happens because people mistakenly apply the general "-th" rule, which applies to most other numbers, without checking the final digit.
Why People Make the "22th" Mistake
Language relies heavily on patterns. Because the vast majority of numbers take the -th suffix, our brains naturally try to apply that rule across the board.
Think about the teens. The numbers 11, 12, and 13 break the standard pattern by taking -th instead of their respective digit suffixes (-1st, -2nd, -3rd). You write 11th, 12th, and 13th. This irregularity trains your brain to associate double-digit numbers with a trailing -th.
When you reach the twenties, the pattern shifts back to matching the final digit.
- 21st ends in 1, so it takes -st.
- 22nd ends in 2, so it takes -nd.
- 23rd ends in 3, so it takes -rd.
- 24th through 29th end in 4 through 9, so they take -th.
Because 24th, 25th, 26th, 27th, 28th, and 29th all use -th, it is easy to slip up and treat 22 the same way. Consistency in language is rare, and numbers provide plenty of exceptions to trip up even careful writers. You can read more about number formatting guidelines on the Chicago Manual of Style Online.
Spelling Out Ordinal Numbers in Full
Sometimes, writing out the words completely is better than using digits, especially in formal invitations or printed greeting cards. When you spell out twenty-two, you also spell out the ordinal suffix.
- Correct: twenty-second birthday
- Incorrect: twenty-twoeth birthday
Notice that you hyphenate the compound number. You do not add extra syllables or weird endings like "-eth" to the word. You simply change the final cardinal word (two) into its ordinal counterpart (second).
Common Mistakes with Milestone Birthdays
Similar spelling traps appear around other ages. People frequently misapply ordinal suffixes to numbers that end in 1, 2, and 3 during their twenties, thirties, and beyond.
- 21st vs 21th: Always use 21st because it ends in 1.
- 22nd vs 22th: Always use 22nd because it ends in 2.
- 23rd vs 23th: Always use 23rd because it ends in 3.
- 31st vs 31th: Always use 31st because it ends in 1.
- 32nd vs 32th: Always use 32nd because it ends in 2.
- 33rd vs 33th: Always use 33rd because it ends in 3.
Memorizing this small set of exceptions prevents embarrassing typos on custom banners, party invitations, or social media posts. For additional guidance on standard punctuation and abbreviation rules, check the resources provided by Merriam-Webster.
Frequently Asked Questions
Is it ever acceptable to write 22th?
No. "22th" is always grammatically incorrect in standard English. The correct form is always 22nd.
How do I pronounce 22nd?
You pronounce it as twenty-second. You do not pronounce it like "twenty-twoth."
Do ordinal numbers need a superscript?
You can write ordinal indicators on the baseline (22nd) or as superscripts ($22^{nd}$). The baseline style is much more common in modern digital publishing and professional writing because it is easier to read and format across different screens.
How do I write the date for a birthday?
When writing a date that includes an ordinal number, you can write "July 22nd" or "the 22nd of July." Both formats are correct, though many style guides recommend dropping the suffix when the day precedes the month, such as writing "July 22."
