KoguNavi

Age Calculator

Enter a birth date and reference date to see practical Japanese age details without sending dates away.

Local in browser

Runs in your browser for this tool. Input is not uploaded.

What it helps with

  • Check age for Japanese forms
  • See kazoedoshi and zodiac quickly
  • Estimate school-year timing for a child

How to use

  1. Enter a birth date using the calendar picker or manual YYYY-MM-DD input.
  2. Choose a reference date, or use today.
  3. Calculate and review full age, kazoedoshi, zodiac, school-year hints, and milestones.

Examples

Before birthday

Input

2000-07-10 | 2026-07-05

Output

Full age: 25

After birthday

Input

2000-07-10 | 2026-07-10

Output

Full age: 26

School year hint

Input

2018-04-02 | 2025-04-10

Output

Elementary grade 1

Good to know

  • School year, yakudoshi, and longevity celebrations are practical estimates.
  • Local school paths, customs, and official form rules can vary.
  • This tool is not legal, medical, or administrative advice.

FAQ

Does this calculate kazoedoshi?
Yes. It shows both full age and kazoedoshi for the selected reference year.
Are school year results official?
No. They are practical estimates based on the common Japanese April 2 cutoff and April school year.
Are the dates uploaded?
No. The calculation is designed to run in your browser for this tool.

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