Ordinal Numbers
An ordinal number tells you the position of something (first, second, tenth). A cardinal number tells you how many (one, two, ten). Most ordinals add -th to the cardinal, with a few irregulars.
Rules
- Irregulars: first, second, third, fifth, eighth, ninth, twelfth — memorize these.
- Numbers ending in y: change the y to ie before adding th → twentieth, thirtieth, fortieth.
- Compound ordinals: only the last word takes the ordinal form → twenty-first, not twentieth-first.
- Use the short form (1st, 2nd, 22nd, 101st) for numerals, the written form in formal prose.
Examples
| Input | In words |
|---|---|
| 1 | 1st — first |
| 2 | 2nd — second |
| 3 | 3rd — third |
| 4 | 4th — fourth |
| 5 | 5th — fifth |
| 8 | 8th — eighth |
| 9 | 9th — ninth |
| 12 | 12th — twelfth |
| 20 | 20th — twentieth |
| 21 | 21st — twenty-first |
| 30 | 30th — thirtieth |
| 50 | 50th — fiftieth |
| 100 | 100th — one hundredth |
See also
- Spelling Money Amounts
How to write dollar amounts in words — for checks, contracts, and legal documents. Examples from $1 to $1,000,000. - Writing Numbers on a Check
Step-by-step: how to spell the amount on a US check, including cents, the word 'and', and common mistakes. - Writing Dates in Words
How to write dates like 'April 23, 2026' or 'the 23rd of April' in full English words. - Saying Phone Numbers in Words
Standard ways to pronounce and write out a US phone number digit by digit. - Spelling Fractions
Fractions in English combine a cardinal (top) with an ordinal (bottom). Here's the rule and a table of common fractions. - Spelling Decimal Numbers
How to read and write decimals like 3.14 or 0.005 in English — digit by digit after the point. - Spelling Negative Numbers
Negatives are spelled with the word 'negative' (or 'minus') before the number. - Million, Billion, Trillion, and Beyond
The short-scale names for large numbers used in the US — million, billion, trillion, quadrillion, and up.