Nine Star Ki Calculator

The three numbers

A Nine Star Ki profile is written as three numbers, for example 1.5.1:

• Principal number (year star) — the star in the centre of the Lo Shu square in your solar birth year. It's the broadest number, traditionally linked with your basic nature and how others see you.
• Character number (month star) — the star in the centre in your solar birth month. Traditionally linked with your emotional character and how you were as a child.
• Energetic number (also called the tendency or behavioural number) — derived from the other two: principal minus character plus five, counted round the nine. It's read as how you tend to act under pressure.

Why the start of spring and solar months matter

The Nine Star Ki year begins at the start of spring (Lichun, around 4 February), and each month begins at a solar term, between the 4th and the 8th of the Western month. Someone born on 3 February belongs to the previous year; someone born on 5 March may still belong to the February month. This calculator uses the exact solar term dates for 1900–2100 rather than fixed dates.

The nine stars

Nine Star Ki and the Kua number

The principal number uses the same arithmetic as the annual flying star and a man's Kua number, so for men the two usually agree. Kua numbers use a different formula for women and never take the value 5, so for women they usually differ. They belong to different systems — Kua to Eight Mansions feng shui, Nine Star Ki to a Japanese-developed astrology based on the same Lo Shu square.

Principal numbers by year, 1930–2030

The year begins at the start of spring shown.