Japan Toolbox

Free calculators and converters for life in Japan: Japanese era years, public holidays, consumption tax, school years and room sizes, explained in plain English. Everything runs in your browser, so nothing you type is sent anywhere.

Dates & calendar

• Japan Public Holidays List and Long WeekendsPick a year to see every national holiday in Japan, plus each run of three or more days off.
• Japanese School Year & Age Calculator (Early-Born "Hayaumare")Enter a date of birth. You get the Japanese school grade on any date, school entry and graduation years, the early-born status, and age the Japanese way.
• Japanese Era Converter (Reiwa, Heisei, Showa ↔ Western Year)Type a Western year, a Japanese era year such as "R7" or "平成31年", or a full date. The result updates as you type.

Money & tax

• Japan Consumption Tax Calculator (10% and 8%)Enter a price in yen. You get the price with and without tax, the tax amount, and whether it reaches the tax-free shopping minimum.

Housing & living

• Tsubo and Tatami (Jō) to m² and ft² ConverterEnter a size in tsubo, tatami (jō), m² or ft². You get all the other units at once, including five different tatami sizes.

Why use these tools

• No sign-up and no app. They work on your phone as they are.
• Your input never leaves your device, so you can safely enter birth dates and prices.
• Every tool shows the Japanese rule behind the result and links it to the official source, so you can check the answer.