About Ajamall Calculators
Ajamall Calculators is a family site of the Ajamall portal (Korean), Ajamall Health Calculators and Ajamall Unit Converters. It collects interest and savings, loan and repayment, investing and returns, everyday and math and statistics calculators (32 in all) in Korean, English and Japanese.
Why we built it
There are many financial calculators, but it is often hard to tell where the amount you type goes, and many do not say how they calculate and round. A salary, a loan amount or your savings are numbers you may not want anyone else to see. So this site does all its calculation in your browser and states the calculation method and rounding rule of each calculator.
Our rules
- What you enter is not sent to a server or stored. The calculators do not call outside services to work.
- Values that can change, such as tax rates, limits and rate benchmarks, are used only when we opened the official source ourselves, and we show the source and the date. We do not write down what we could not confirm.
- Amounts are calculated with exact numbers (fractions) so that floating-point error does not creep in. A few calculations that need logarithms or roots are marked as approximate on screen (see How we calculate). The rounding rule and the way days are counted are stated in each calculator.
- Each calculator has tests, and the expected values come from hand calculation or from examples in official documents. We do not copy the tool's own output as the answer.
- A result means "calculated with these inputs, this is what comes out". It is a reference calculation, not a judgment about your situation or a recommendation.
Found a mistake?
If a result or an explanation differs from the official document, tell us through the Ajamall portal contact page (in Korean). We fix confirmed errors and record the date.
About the operator
- This is a private website, not a financial institution or a public body.
- The code and the explanatory text were written with the help of AI, and the values and rules were checked against original documents and hand calculation as described above.
- The site may show Google AdSense advertisements. Ads do not change the results. See Privacy for details.
- Results are for reference. Before an important decision such as a loan, an investment or taxes, check directly with the financial institution or a professional. Please also read the Disclaimer.