Ordinal Number Converter
Enter a whole number and get its ordinal two ways: the suffix form (22nd) and the spelled-out form (twenty-second). Switch to batch mode to convert a list, one number per line, and see the suffix rules in a table beside the result. Free, no sign-up.
Mode
Ordinal suffix rules
| Rule | Suffix | Examples |
|---|---|---|
| Last digit is 1 (not 11) | st | 1st, 21st, 101st |
| Last digit is 2 (not 12) | nd | 2nd, 22nd, 142nd |
| Last digit is 3 (not 13) | rd | 3rd, 33rd, 103rd |
| Ends in 11, 12, or 13 | th | 11th, 12th, 113th |
| Everything else | th | 4th, 9th, 20th, 100th |
The teens exception is the one everyone trips over: 11, 12, and 13 always take "th" because they are pronounced eleventh, twelfth, thirteenth — so 111th and 112th are correct, while 21st and 22nd follow the last-digit rule.
How to Use the Ordinal Number Converter
- 1. Pick a mode. Single number converts one value as you type. Batch converts a list.
- 2. Enter whole numbers. Type 22, or in batch mode put one number on each line. Zero and up are accepted; decimals and negative numbers are not.
- 3. Read both forms. Each number comes back as a suffix ordinal (22nd) and spelled out (twenty-second), with a Copy button. In batch mode Copy All copies the whole list.
- 4. Check a rule. The table at the bottom shows how the suffix depends on the last digits.
The Suffix Rules
An ordinal number names a position — first, second, third — where a cardinal number names a quantity. In digits, the ordinal takes a two-letter suffix, and the choice depends on the last one or two digits:
| The number ends in… | Suffix | Examples |
|---|---|---|
| 1, but not 11 | st | 1st, 21st, 101st |
| 2, but not 12 | nd | 2nd, 22nd, 142nd |
| 3, but not 13 | rd | 3rd, 33rd, 103rd |
| 11, 12 or 13 | th | 11th, 12th, 113th |
| Anything else (0, 4–9) | th | 4th, 9th, 20th, 100th |
The teens exception is the one people trip on. Eleven, twelve and thirteen already have irregular names (eleventh, twelfth, thirteenth), so every number ending in 11, 12 or 13 takes th — 111th and 112th are correct — while 21st and 22nd follow the last-digit rule.
Spelling Ordinals Out
To spell an ordinal, write the number in words and change only the last word. Seven words are irregular: one → first, two → second, three → third, five → fifth, eight → eighth, nine → ninth and twelve → twelfth. A word ending in -y becomes -ieth (twenty → twentieth); every other word just adds th.
| Number | Suffix form | Spelled out |
|---|---|---|
| 1 | 1st | first |
| 12 | 12th | twelfth |
| 21 | 21st | twenty-first |
| 40 | 40th | fortieth |
| 101 | 101st | one hundred first |
| 111 | 111th | one hundred eleventh |
| 1000 | 1000th | one thousandth |
The tool shows large numbers without separators (1000th) and, in American style, spells out 101st as "one hundred first" without an and; add it by hand if you want the British form. Word processors may turn 21st into a superscript automatically — you can switch that off in autoformat settings if your style guide asks for full-size suffixes.
Ordinals in Academic Writing
- Not in dates. APA, MLA and Chicago write dates with plain numerals — July 28 or 28 July 2026 — not July 28th.
- Where they belong. Rankings (the 3rd quartile), editions (2nd ed.), centuries (the 19th century or the nineteenth century), grades and sequences.
- Words or numerals. Ordinals usually follow the same spell-out rule as cardinals in your style: small ones in words, larger ones in numerals. For the cardinal rules, see the Number to Words Converter.
Typing Large Numbers
Thousands separators are fine
Type 1000, 1,000 or 1.000 and each comes back as 1000th: a comma or dot followed by exactly three digits is read as a thousands separator. Any other separator, as in 2,5 or 1.5, makes a decimal, and the converter accepts whole numbers only.
Which Tool Do You Need?
| You want to… | Use |
|---|---|
| Write 1st, 2nd, 3rd or first, second, third | This converter |
| Write ordinary numbers in words (forty-two) | Number to Words Converter |
| Turn written numbers back into digits | Words to Numbers Converter |
| Write ordinals in Spanish, French or German | Spanish, French and German Number Converters |
| Number a series with Roman numerals | Roman Numeral Converter |
Frequently Asked Questions
- What is an ordinal number?
- An ordinal number gives position or rank — 1st, 2nd, 3rd, 4th — where a cardinal number (1, 2, 3, 4) gives quantity. In words, the ordinals are first, second, third, fourth and so on.
- Why is 11 written 11th and not 11st?
- Numbers ending in 11, 12 or 13 always take th, as in 11th, 12th, 13th, 111th and 212th, because eleventh, twelfth and thirteenth are irregular words. The st, nd and rd suffixes apply only when the last digit is 1, 2 or 3 outside those endings, so 21st and 22nd are correct and 11st and 12nd are not.
- How do I spell out ordinal numbers?
- Write the number in words and make only the last word ordinal: 22 is twenty-second, 45 is forty-fifth and 130 is one hundred thirtieth. The irregular forms are first, second, third, fifth, eighth, ninth and twelfth, and words ending in -y change to -ieth.
- Should I use ordinals in dates in academic writing?
- No. APA, MLA and Chicago all write dates with cardinal numerals — July 28 or 28 July 2026, never July 28th. Use ordinals for rankings, editions, centuries and sequences.
- Can I convert a whole list of numbers at once?
- Yes. Switch to batch mode and enter one number per line. Each line is converted to its suffix form and its spelled-out form, and Copy All copies the result. A line that is not a whole number is marked as such.
- Is zero an ordinal?
- The tool accepts 0 and returns 0th and zeroth, which are used in counting from zero in mathematics and programming. In everyday English there is no ordinal for zero, and 1st is the first position.