lodestarA zodiac sign covers 30 degrees. Some Western astrology traditions divide each sign into three smaller parts called decans, or faces.
Each sign has three decans
The first runs from 0° to just before 10°, the second from 10° to just before 20°, and the third from 20° to just before 30°. The three-part count starts again with each new sign.
Try 18° Leo as an example
If a chart lists the Sun at 18° Leo, first find the sign: Leo. Since 18° falls between 10° and 20°, that position is in Leo's second decan. The word “second” identifies a section; it is not a score.
The extra label is optional
Some astrologers link each decan with a traditional planet or image, and the methods differ. You can begin reading a chart without this extra layer. A decan alone cannot settle anyone's character or future.
A few common questions
Is the second decan a different zodiac sign?
No. It is still part of the original sign. Decan only tells you which ten-degree section within that sign contains the position.
Sources & further reading
Astrology sources describe their own traditions and methods; they do not establish predictive accuracy. The writing exercises are original Lodestar editorial material.