Twelve equal slices
A sign is one of twelve equal 30° divisions of the zodiac. The count starts at Aries at 0° and runs once around the ring through Taurus, Gemini and on to Pisces. A body's longitude says which slice it is in: any longitude from 0° up to 30° is Aries, from 30° up to 60° is Taurus.
Inside a sign the position is written in degrees and arcminutes, from 0°00′ to 29°59′. At 30° the next sign begins, and at 360° the ring closes: Pisces ends where Aries starts.
Elements and modalities
Astrology sorts the signs two ways. The element is fire, earth, air or water, with three signs each. The modality is cardinal, fixed or mutable, with four signs each. The two groupings cross, so every sign has a unique pair.
Cardinal signs open a season, fixed signs sit in the middle of one and mutable signs close one. Signs of one element sit four apart, 120° from each other, and opposite signs always share a modality: Aries and Libra are both cardinal. Tap a sign to light it on the wheel.
Each box is one sign. The wheel shows the four element colors until you pick one.
Signs are not constellations
The signs share names with constellations, but they are not the same thing. In the tropical zodiac a sign is a 30° slice measured from the March equinox, so it follows the seasons. Constellations vary in width, and the sky has drifted since the names were given. Lesson 11 shows what that does to a chart.
Try it on your chart
See your signs
Your chart colors every sign by its element, so the four hues you see in this lesson are the ones on your wheel.