Why this site exists
Individual investors run into the same calculations again and again: average purchase price, compound growth, capital gains tax, severance pay. Each time, many of us open a spreadsheet and rebuild the formulas, or jump between ad-heavy sites and compare their answers. MoneyCalcs was built to cut that repetition. You open a page, enter your numbers and see the result at once, and the formula and the basis behind it are on the same page.
How each calculator is built and checked
- Standard formulas. Where a calculation has an established formula, such as compound interest, present value or loan payments, we implement that formula as is and write it out under "How it works" on the page.
- Laws and reference dates. Tax and insurance calculators follow the relevant laws and public material, such as the Korean Income Tax Act and National Tax Service tables or the IRS figures for US tools, and each page shows the reference date it applies.
- Cross-checking. We compare each result with spreadsheet calculations built by hand and with worked examples published by public agencies, and we test extreme inputs such as zero or very large values. We cannot guarantee every case, so please also check official sources before filing taxes or signing a contract.
Update policy
When a law or rate changes, we update the calculator together with its new reference date. Proposed tax changes that have not been enacted are not treated as final and are labeled as proposals. When someone reports an error, we check it, correct it if it is confirmed, and change the last-modified date on that page. Exchange rates and market data are market-close values or values from a public exchange-rate API, not real-time quotes.
What we do not do
- We do not give investment advice or recommend stocks. A stock or product named as an example is not a buy or sell opinion.
- We do not give personal investment, tax or legal advice.
- There is no sign-up, and the values you enter are not sent to or stored on a server. If you copy a result link, your inputs are included in the web address.
Operation and contact
MoneyCalcs is free to use, and pages may show Google AdSense ads. We do not publish the operator's name or background. Instead, we publish the formulas, sources and reference dates so anyone can verify a result. Send bug reports, questions about our calculation basis, and partnership or removal requests to contact@robin-invest.com. We aim to reply within 3 business days. See the Contact page for details.
Our principles
- We do not make recommendations. MoneyCalcs only provides data and calculation tools and does not encourage buying or selling any particular stock.
- We state our sources and reference dates. Tax, fee and exchange-rate data are always shown with their source and reference date.
- We do not collect personal data. There is no sign-up, and calculation inputs are not stored except in the shareable link (URL).
Data sources
Historical prices in the DCA calculator come from Naver Pay Securities (Korean index and stock monthly bars), Yahoo Finance (month-end closes for overseas indexes, stocks, Bitcoin and gold) and the US Federal Reserve (FRED, month-end exchange rates). Currency conversion uses Naver Pay Securities for the dollar-won rate and a public exchange-rate API (open.er-api.com). ETF holdings come from each ETF issuer, and tax and rule references come from the National Tax Service, the Ministry of Economy and Finance (formerly the Ministry of Strategy and Finance), the Ministry of Health and Welfare, the National Pension Service and the relevant laws. Detailed sources are at the bottom of each page.