What your chart shows
Human Design, a system Ra Uru Hu developed from 1987, maps two moments onto a figure of the body called the bodygraph. The first is your birth: the Sun and the Earth opposite it, the North and South Nodes of the Moon, the Moon and the planets from Mercury to Pluto. The second is the moment the Sun stood 88° earlier, about three months before you were born. Each of those 26 positions falls in one of 64 gates, and each gate belongs to one of nine centers.
A channel joins two gates in different centers. When both of its gates are active, the channel is defined, and so are the two centers it joins. Everything else in the chart follows from those defined channels: your type, your inner authority, your definition. Your profile comes from the lines of the two Suns, and your incarnation cross from the gates of the two Suns and Earths.
How it is calculated
The planets come from the same ephemeris as every chart on this site, which is checked against NASA JPL Horizons and the Swiss Ephemeris. The gates run in the order of the Human Design wheel from Gate 41 at 2° Aquarius, each 5°37′30″ wide and each divided into six lines of 56′15″. The nodes are the true nodes. The Design moment is found by solving for the instant the Sun stood exactly 88° behind its birth position.
The rules are applied as the system defines them: type from whether the Sacral is defined and whether a motor reaches the Throat, authority in its fixed order of precedence, definition from the connected groups of defined centers. The site's tests reproduce three published reference charts, their type, authority, profile, definition and cross and every channel the sources list, and check each rule case by case.
Your type in one line
On 10,000 birth moments spread evenly over 1950 to 2009, 38% of charts come out as Generators, 31% as Manifesting Generators, 22% as Projectors, 8% as Manifestors and 0.9% as Reflectors. The guide to the five types explains what decides each one and how it is read.
Authority, profile and definition
Your inner authority is how Human Design says you make decisions well: an emotional wave, a gut response, a flash of intuition, and so on. About half of all charts have emotional authority. Your profile is two numbers from 1 to 6, the lines of your conscious and unconscious Suns, read as a costume or role; six profiles are common and six are rare, as the profiles guide shows. Definition says whether your defined centers form one connected whole or two or more separate groups.
Your birth time and the chart
The Sun moves one line in about a day, so your profile rarely depends on the hour, but the Moon moves one line in about two hours and a gate in ten. With a birth time, the calculator shows the span of times over which every fact in your chart stays the same, so you can see whether a rounded or approximate time could change it. Without one, it lists which facts hold all day. The four arrows beside the Head, the Variable, are finer still: the Sun turns its two arrows about every two hours, and the calculator gives their own span.