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Number to Ordinal Converter

Convert integers to ordinal form: 1 → 1st, 22 → 22nd, 113 → 113th.

Output will appear here…
Total Inputs: 0Characters: 0
Quick Reference
11st22nd33rd44th1010th1111th1212th1313th2020th2121st100100th101101st111111th10011001st

Ordinal suffix rules

English ordinal suffixes follow a simple pattern with one important exception. The general rule: 1 → st, 2 → nd, 3 → rd, 4–9 → th. The exception: numbers ending in 11, 12, or 13 always use thregardless of the tens digit — so 11th, 12th, 13th (not 11st, 12nd, 13rd), and also 111th, 112th, 113th. This applies to negative integers too: -1st, -11th. Related: word to number converter.

Built and maintained by Meet Shah · Last updated

What this tool is used for

  • Producing an ordinal form for a date or a ranking in copy.
  • Generating ordinals for a numbered list in prose.
  • Checking the suffix for a number whose rule you cannot recall.
  • Producing ordinals for a template that formats positions.
  • Converting a batch of positions consistently.

Frequently Asked Questions

What is the rule for the suffix?
Look at the last two digits first: 11, 12 and 13 always take `th`. Otherwise the last digit decides — 1 takes `st`, 2 takes `nd`, 3 takes `rd`, everything else `th`. Checking only the last digit is the bug that produces 11st, 12nd and 13rd.
Why are the teens an exception?
Because the words are irregular in English — eleventh, twelfth, thirteenth — and the suffix follows the pronunciation rather than the digit. The pattern resumes at 21st, which is why the modulo-100 check is only needed for that one band in each hundred.
What about 111 and 112?
They follow the teens rule, because 111 mod 100 is 11 — so 111th and 112th, not 111st and 112nd. That is exactly why the check is against the last TWO digits rather than a hard-coded list of 11, 12 and 13.
Does it handle negative numbers?
It applies the same suffix logic to the absolute value, so −1 becomes −1st. Ordinals of negative numbers are unusual in ordinary English but appear in indexing and offsets, where the sign is a direction rather than a count.
Are ordinals different in other languages?
Substantially. Many languages inflect the ordinal for gender, number and case, so a single suffix rule does not exist. `Intl.PluralRules` with `type: 'ordinal'` is the correct API for anything localised — hard-coding English suffixes is the classic i18n bug.

Common errors and gotchas

  • Applying the simple last-digit rule to 11, 12 and 13, which take 'th' rather than 'st', 'nd', 'rd'.
  • Assuming 111 follows 1, when it follows 11 and takes 'th'.
  • Using English suffixes in another language, where ordinals are formed differently.
  • Superscripting the suffix in a context that will be read aloud or parsed.
  • Producing an ordinal for zero or a negative, which most conventions leave undefined.

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