Turn a whole number into its English order form, such as 21st and twenty-first.
21 becomes 21st (twenty-first). The endings 11, 12, and 13 use th, so 111 becomes 111th.
twenty-first
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How to Use the Ordinal Number Converter
Enter the position of an item in a list or sequence. The converter shows both the compact number form (21st) and the English word form (twenty-first). The input range is 1 through 999,999,999.
English Ordinal Suffix Rules
Most numbers use th. Numbers ending in 1, 2, or 3 normally use st, nd, or rd. The 11, 12, and 13 endings are exceptions and use th, including 111th, 112th, and 113th.
Writing Ordinal Numbers in Words
The last spoken word changes to its ordinal form: twenty-one becomes twenty-first, one hundred becomes one hundredth, and one hundred and twelve is commonly written one hundred twelfth in this converter’s US English style.
Dates and publication styles can have different conventions for how much of an ordinal is spelled out.
Cardinal and Ordinal Numbers
A cardinal number gives a quantity: “There are 21 students.” An ordinal number gives a position: “She finished 21st.” Use this converter for positions, ranks, floors, and ordered lists.
Common Ordinal Mistakes
Why is 11th correct rather than 11st?
Numbers ending in 11, 12, or 13 take th even though their last digit is 1, 2, or 3.
Is 0th a normal list position?
Most everyday ordered lists begin at first position, so this converter starts at 1.
Are ordinal and cardinal numbers interchangeable?
No. Cardinal numbers count items; ordinal numbers show order or position.
Ordinal Number FAQs
What is the ordinal of 21?
21st, written twenty-first.
What is the ordinal of 112?
112th, written one hundred twelfth.
What is the ordinal of 1000?
1000th, written one thousandth.
Editorial review
SolverCalc names Prof. Dr. Khalil Mudassar as its educational reviewer. The English ordinal rules can be checked against the references below.
Sources
Disclaimer
For educational use. Check your class or textbook convention when the problem defines a different range, sequence index, or notation.