About RenewPage Tools

RenewPage Tools is a small collection of free calculators for everyday money, work, date and school questions. It is made by RenewPage, a small web studio that redesigns websites for small businesses.

Who runs this site

RenewPage is operated by a sole proprietorship registered in the Republic of Korea (trade name: 스매일, business registration number 673-30-01804).

Address: 107/202, 161 Gopung-ro, Ilsandong-gu, Goyang-si, Gyeonggi-do 10302, Republic of Korea
Email: hello@renewpage.com

How the calculators are made

• Each calculator states the formula it uses and walks through one example you can check by hand.
• The calculation code is tested against hand-worked and published examples before each release.
• Each page links to the government agency, regulator or standards body page that describes the method or the rules involved.
• The page text was drafted with the help of AI writing tools and then edited and checked against those sources. Translations were also produced with AI tools; the formulas and calculation code are the same in every language.
• Everything runs in your browser. The numbers you type are not sent to us or stored.

What these tools are not

The results are estimates for planning and learning. They are not financial, tax, legal, academic or other professional advice. See our Terms & Disclaimer.

Found a mistake?

If a result looks wrong or a source has changed, please email hello@renewpage.com with the page and the numbers you entered. We review every report.