About JapanCalc

What is JapanCalc?

JapanCalc is a free collection of bilingual (English + Japanese) online calculators and converter tools for anyone who interacts with Japanese administrative, financial, or language systems. All tools run entirely in your browser — no server, no account, no data collection.

Whether you are a foreign resident filling out Japanese government forms, a tourist trying to understand consumption tax prices, or a Japanese language learner looking up era dates and kanji — JapanCalc is built for you.

Our Tools

JapanCalc currently offers the following free tools:

• Japanese Era Date Converter — convert between Japanese era years (Reiwa, Heisei, Showa) and the Western calendar
• Consumption Tax Calculator — add or remove Japan’s 10% / 8% consumption tax from any price
• Japanese Age Calculator — calculate 満年齢 (official age) and 数え年 (traditional age)
• Japanese Zodiac Calculator — find your eto animal sign, traits, and compatibility

More tools are in development, including a salary take-home calculator, romaji converter, furigana generator, and more.

How It Works

Every JapanCalc tool is 100% client-side. When you enter a date, price, or year into a calculator, all computation happens in your browser using JavaScript. Nothing is sent to any server. Your inputs are never stored, logged, or shared.

The site is hosted on Cloudflare Pages and delivered via Cloudflare’s global content delivery network for fast load times worldwide.

Data Sources

JapanCalc uses official data sources for all calculations:

• Era dates: Japan Cabinet Office
• Tax rates: National Tax Agency Japan (NTA)
• Public holidays: Cabinet Office — Public Holiday Law

All tools are provided for reference purposes only. For official or legal matters, always verify with the relevant Japanese authority.

Contact

Questions, feedback, or data corrections: [email protected]