Where it comes from
Human Design is a system created by Ra Uru Hu, the name taken by Alan Robert Krakower, a Canadian born in 1948, who said it was revealed to him in a mystical experience in 1987, on the island of Ibiza by his own account. He taught it until his death in 2011, and Jovian Archive, the company he founded, holds the rights to his work. The system presents itself as a synthesis of older traditions: the planets and zodiac of Western astrology, the 64 hexagrams of the Chinese I Ching, the Tree of Life of the Kabbalah and the chakras of Hindu tradition, joined with ideas Ra took from physics and genetics.
How a chart is built
A Human Design chart, the bodygraph, is calculated from two moments. The first is your birth, called the Personality and drawn in black on most charts (this site draws it light against a night sky, and black when printed): it is read as the part of you that you know. The second, called the Design and drawn in red, is the moment about three months earlier when the Sun stood exactly 88° behind its place at birth: it is read as the part of you others see first. At each moment the positions of thirteen points, the Sun and the Earth, the two lunar nodes, the Moon and the planets from Mercury to Pluto, fall in one of 64 gates, each a slice of the zodiac 5°37′30″ wide.
The gates sit in nine centers drawn on the body, from the Head at the top to the Root at the base. A channel joins two gates in different centers, and when both of its gates are active the channel is defined, along with the two centers it joins. The rest of the chart follows from what is defined. The free Human Design chart calculator draws yours and explains each part.
The five types
Your type comes from two questions: is the Sacral center defined, and is a motor (the Sacral, Heart, Solar Plexus or Root) connected to the Throat? The answers give five types: Generators, Manifesting Generators, Projectors, Manifestors and Reflectors. Each has a strategy, the way the system says it meets life best, and a not-self theme, the feeling that signals it has lost its way. The guide to the five types covers each one with how common it is.
Authority, profile and definition
Your inner authority is how the system says you make decisions well, decided by which centers are defined, in a fixed order of precedence: the eight authorities run from the emotional wave of the Solar Plexus to the Reflector's lunar cycle. Your profile, two numbers such as 1/3 or 6/2, comes from the lines of your two Suns and is read as the role you play; the twelve profiles are not equally common. Your definition says whether your defined centers make one connected whole or separate groups.
Centers, channels and gates
The nine centers each have a theme: the Head for inspiration, the Ajna for thinking, the Throat for speech and action, the G for identity and direction, the Heart for willpower, the Spleen for intuition, the Solar Plexus for emotions, the Sacral for life force and the Root for pressure. A defined center is read as a consistent part of you; an open one as where you take in and amplify other people. The 36 channels are read as your fixed gifts, and the 64 gates as the individual themes within them. How your defined centers connect, in one piece or in separate areas, is your definition.
How to read your chart
Start with your type and strategy, the part the system puts first, then your inner authority. Next look at your defined and open centers, and at your channels. Profile and incarnation cross come after, as the larger themes of a life, and the four arrows of the Variable, the most detailed layer, last. The tradition's own advice is to experiment: to try living by your strategy and authority and see what changes, rather than take any reading on faith. To read two people together, the Human Design compatibility chart lays one bodygraph over the other.
Human Design and astrology
Human Design uses the same planetary positions as a birth chart but reads them in its own way, with no signs, houses or aspects. If you want the astrological view of the same moment, the birth chart calculator gives the planets in signs and houses, and your astrocartography map shows where on Earth each planet was angular when you were born.