How to Convert Numbers to Hanja (Formal Chinese Numerals) — Amount Notation for Contracts & Deeds
Jun 23, 2026
If you've ever filled in an amount on a Korean contract, promissory note, or official deed, you've likely encountered characters like 壹百萬圓整. These are formal Hanja numerals — complex Chinese characters used specifically to make monetary amounts tamper-proof. Simple Arabic numerals (1, 2, 3…) and ordinary Chinese numerals (一, 二, 三…) have so few strokes that a tiny pen mark can change one number into another. Formal Hanja characters are deliberately more intricate, so any alteration is immediately obvious.
Type a number and get the formal Hanja equivalent instantly. Free, no signup required.
Convert Now →What Are Formal Hanja Numerals?
Formal Hanja numerals (갖은자, literally "fully-stroked characters") are elaborate variants of ordinary Chinese numeral characters. They have been used for centuries across Korean, Chinese, and Japanese legal and financial documents to prevent fraudulent alteration of written amounts.
Consider the ordinary character 一 (1) — a single horizontal stroke. Add a stroke before it and you get 二 (2) or even 三 (3). Now compare with 壹 (formal 1): its dense structure makes any unauthorized modification visually apparent at once. That is why promissory notes, checks, deeds, and loan agreements use formal Hanja numerals for the amount field.
Why Are Formal Hanja Numerals Still Used?
- Fraud prevention — The complexity of each character makes it extremely difficult to alter a written amount without detection, providing a strong safeguard against forgery.
- Legal weight — On real-estate sale contracts, money-lending agreements, and other legally binding documents, formal Hanja notation strengthens the evidentiary value of the original amount in case of disputes.
- Promissory notes and checks — Korean banking practice traditionally requires the amount on a promissory note or check to be written in formal Hanja or Korean spelled-out form (일금 ~원정), or both.
- Notarized documents and IOUs — Even informal IOUs and notarized documents often include formal Hanja amounts to reduce the risk of after-the-fact tampering.
Formal Hanja Numeral Reference Table
| Number | Ordinary Hanja | Formal Hanja (갖은자) | Reading |
|---|---|---|---|
| 1 | 一 | 壹 | il |
| 2 | 二 | 貳 | i |
| 3 | 三 | 參 | sam |
| 4 | 四 | 肆 | sa |
| 5 | 五 | 伍 | o |
| 6 | 六 | 陸 | yuk |
| 7 | 七 | 柒 | chil |
| 8 | 八 | 捌 | pal |
| 9 | 九 | 玖 | gu |
| 10 | 十 | 拾 | sip |
| 100 | 百 | 佰 | baek |
| 1,000 | 千 | 仟 | cheon |
| 10,000 | 萬 | 萬 | man |
* 萬 (10,000) uses the same character in both ordinary and formal Hanja.
How to Convert — 2 Steps
- Enter the number — Open the FreeSign Hanja Number Converter and type the amount. Example:
1,500,000 - Copy the result — The tool outputs the formal Hanja string (e.g., 壹佰伍拾萬) and optionally the Korean spelled-out form (일금 일백오십만원정). Paste directly into your contract, deed, or note. No installation or account needed.
The converter supports both ordinary Hanja (一·二·三 style) and formal Hanja (壹·貳·參 style), so you can choose the appropriate format for your document.
Useful Companion Tools
Korean contracts typically pair formal Hanja amounts with a Korean spelled-out amount (일금 ~원정 format). Use the Number to Korean Amount converter to generate "일금 삼천오백만원정" in one click. For a deeper guide on Korean amount notation conventions, see the Korean Amount Writing Guide.
Frequently Asked Questions
Q. What is the difference between ordinary Hanja numerals (一·二·三) and formal Hanja (壹·貳·參)?
Ordinary Hanja numerals have very few strokes, making it easy to alter one character into another with a simple pen mark. Formal Hanja characters (갖은자) have dense, complex stroke patterns — any unauthorized modification stands out immediately. This tamper-resistance is why formal Hanja is used on legally binding financial documents.
Q. Is formal Hanja notation legally required on Korean contracts?
It is not strictly mandated by law for all contracts, but writing monetary amounts in formal Hanja (or Korean spelled-out form) alongside the Arabic numeral is strongly recommended practice. It significantly strengthens the evidentiary value of the stated amount in the event of a dispute. Promissory notes and checks traditionally require it under Korean banking conventions.
Q. How do I write the Korean "일금 ~원정" spelled-out amount?
Use the Number to Korean Amount converter. Enter any number and it immediately produces the "일금 오백만원정" format used on Korean contracts. You can use it alongside the Hanja converter to fill in both fields at once.
Q. Is the tool free? Is my data stored?
Completely free. The numbers you enter are processed in your browser and are not stored on any server. No account or installation is required.