Nine centers on the body
The bodygraph draws nine centers on the outline of a body, each with a shape and a traditional color. From the top: the Head, a triangle pointing up, and the Ajna, a triangle pointing down, are the pressure and awareness of the mind. The Throat, a square, is where speech and action happen. The G, a diamond at the heart of the chart, holds identity, love and direction. Beside it the small Heart holds willpower. On the left the Spleen is the center of intuition and health; on the right the Solar Plexus is the center of emotions. Below, the Sacral is the life force, and the Root at the base is the pressure to act.
Defined and open
A center is defined when a completed channel touches it, and Human Design reads it as a fixed, reliable way you work: a defined Sacral, for example, is steady energy for the right work. An open center, not touched by any defined channel, is read as where you take in other people's energy and amplify it, which the system calls both a source of wisdom and a place where you can be conditioned. Active gates in an open center are called hanging gates, drawn on the bodygraph but not completing a channel.
Motors and awareness
Four centers are motors: the Sacral, the Heart, the Solar Plexus and the Root. Whether one of them reaches the Throat through defined channels decides whether a chart can manifest, which is half of what decides its type. Three centers are called awareness centers: the Ajna (mental awareness), the Spleen (instinctive awareness in the moment) and the Solar Plexus (emotional awareness that comes with time). The Head and the Root are pressure centers.
Nine centers, not seven chakras
Human Design presents its nine centers as a change from the seven chakras of Hindu tradition, one it says took place in 1781, the year Uranus was discovered, and it calls people born since then nine-centered. The claim is the system's own, not something that can be tested, but it explains why the bodygraph's centers echo the chakras without matching them one for one.
How often each is defined
On 10,000 birth moments spread evenly over 1950 to 2009, the Sacral and the Throat are each defined in 69% of charts, the Root and the G in 60%, the Spleen in 58%, the Solar Plexus in 52%, the Ajna in 47%, the Heart in 35% and the Head in only 26%. The Head is defined least because it has only three gates and three channels, all to the Ajna. The free Human Design chart calculator shows which of your nine are defined, with what each one means for you.