What is the difference between the two ordinal systems?

Native ordinals add 째 to the native cardinal — 첫째, 둘째, 셋째 — and are used when counting through people or items ('the second child'). Sino-Korean ordinals prefix 제 (第) to the Sino-Korean number — 제1, 제2 — and are standard for chapters, ranks, editions, and formal sequences.

Why is 첫째 irregular?

The native ordinal for 'first' uses the special stem 첫 (as in 첫날, 'first day') rather than the cardinal 하나, giving 첫째. From 둘째 onward the forms are built regularly from the native cardinals with 째.

Why do some compound native ordinals change shape?

Inside compounds the native ones contract the way they do before counters: 하나→한, 둘→두, 셋→세, 넷→네. So eleventh is 열한째 and twenty-second is 스물두째. The tool applies these contractions automatically.

How far do native ordinals go?

Native Korean numerals are typically used up to 99, so native ordinals run 1–99 here. For larger values, or for anything formal, switch to the Sino-Korean 제N form, which has no practical upper limit in everyday use.

Is anything uploaded?

No. Both ordinal systems are computed from built-in numeral tables in your browser. Nothing you enter leaves the page.

Korean Ordinal Number Converter

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Cardinal numbers, written as Korean ordinals

Korean has two number systems, and so it has two ways to form ordinals. The native system adds 째 to native cardinals for counting (‘the third child’), while the Sino-Korean system prefixes 제 to Sino-Korean numbers for chapters, ranks, and formal order. This tool produces both, so you can pick the one that fits your sentence.

How it works

For native ordinals, the cardinal is built from the native ones (하나, 둘, 셋 …) and tens (열, 스물, 서른 …), then 째 is attached. The first is special — it uses the stem 첫 to give 첫째. Inside compounds the ones contract before 째 just as they do before counters, so eleventh is 열한째 and twenty-second is 스물두째.

For Sino-Korean ordinals, the number is rendered in Sino-Korean (일, 이, 삼 …, grouped every ten-thousand by 만, 억) and the prefix 제 is added:

3rd native = 셋째
3rd Sino   = 제삼   (also written 제3)
22nd native = 스물두째

Tips and notes

Use the native form when you are counting through a small set — children, floors, turns. Use the Sino-Korean 제N form for anything ordered and formal: chapters (제1장), editions, world rankings, and dates. Because native numerals fade out past 99, large ordinals are practically always Sino-Korean. For a plain cardinal in either system, use the Korean Number to Words tool.