What this site does
WonLedger is the English edition of 셈장부 (셈장부), a free collection of Korean money calculators. It works out the numbers people living in Korea run into most — take-home pay, severance, minimum wage and weekly holiday pay, annual leave, jeonse and wolse rent, real estate agent fees and apartment sizes — using Korea's 2026 official rates.
The rules behind these numbers are public, but almost all of the explanations are written in Korean, and many English summaries online are years out of date. Each page here shows the result, the formula behind it and the things it leaves out, so you can judge how far to trust the number.
Same engine as the Korean edition
The English calculators run on exactly the same calculation code and rate tables as the Korean edition. Rates are kept in a single place and every calculator reads from it, so when a rate changes, the Korean and English pages change together. The Korean edition has more calculators and guides; English versions are added for the topics most useful to foreign residents.
Where your numbers go
Nowhere. Every calculation runs inside your browser. The salary, deposit or dates you type are not sent to a server and are not stored; refresh the page and they are gone. There is no sign-up and nothing to install. See the privacy policy for details.
Rates and sources
The rates currently in use are as of October 2026. They come from:
- Social insurance rates — National Pension Service, National Health Insurance Service and the Korea Workers' Compensation and Welfare Service
- Income tax rates and deductions — the Income Tax Act (Articles 47, 55 and 59)
- Minimum wage — Minimum Wage Commission notice
- Severance, weekly holiday pay and annual leave — the Labor Standards Act and the Employee Retirement Benefit Security Act
- Rent conversion cap — the Housing Lease Protection Act and the Bank of Korea base rate
- Real estate agent fee caps — the Enforcement Rule of the Licensed Real Estate Agents Act and city and provincial ordinances (Seoul's figures are used)
Insurance rates and the minimum wage change every January, the National Pension income limits every July, and tax rules after the year-end tax law revision. The Bank of Korea base rate is updated whenever it changes.
How results are checked
Whenever a calculator is added or a rate changes, the values are compared against the published rates and the legal text, and typical cases and bracket boundaries are worked out by hand to make sure they match to the won. If an error is found, it is fixed and recorded in the correction log (Korean).
Even so, no calculator can cover every situation. Personal deductions, company rules and visa conditions change the result from person to person. That is why each page has a section on what it does not include. Please read it before relying on a number.
Why there are ads
The site is funded by advertising so the calculators can stay free and up to date. In return, three rules apply:
- Ads never cover the calculator. They appear only between sections and at the bottom.
- Your inputs are never passed to advertisers. What you type is not sent anywhere.
- No tricks to make you click. Ads are not dressed up as content or placed next to buttons.
Report an error
If a result differs from an official calculator, or there is a calculator you need, please tell us through the contact page. Error reports are handled before anything else, because a wrong number is the worst thing this site can show.