How We Calculate and Check Human Design

All positions come from the Swiss Ephemeris, an astronomical calculation library for planetary positions. For births from 1800 to 2399 we calculate with its data files, which are delivered together with our calculation. Outside these years the Swiss Ephemeris falls back to its built-in analytical model.

At each of the two moments we determine 13 points: Sun, Earth, North Node, South Node, Moon, Mercury, Venus, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. Together that makes 26 activations. The Earth always stands exactly opposite the Sun, and the South Node exactly opposite the North Node.

For the lunar nodes we use the true node, the actual oscillating position of the node, not the smoothed mean node. We check that the astrology chart and the Human Design chart place the North Node at exactly the same position, so the two never mix true and mean node.

Planet positions refer to universal time. We therefore convert your local birth time with the time zone of your birthplace as it applied on your birth date, including daylight saving time, wartime time and changed zone offsets. The zone is found from the coordinates of your birthplace.

We check this in 20 birth situations. For each of them the result must match the offset known from the history of that place, and a second, independent time zone calculation must give the same value. Among them are Germany in July 1977 without daylight saving time, Kathmandu before and after the change to +5:45 in 1986, Lord Howe Island with its half hour daylight saving shift, Newfoundland at minus 3:30, and Sydney in March 1990 just after daylight saving time ended.

Your Personality comes from the moment of birth. Your Design comes from the moment when the Sun stood exactly 88 degrees of arc behind its position at birth. We find this moment by iteration until the position of the Sun matches to better than 0.001 degrees.

Because the speed of the Sun in the sky varies over the year, this moment lies between 86 and 93 days before birth, not at a fixed number of days. We measured this across births from 1900 to 2100. For two test charts we check that the Design Sun lies exactly 88 degrees before the Sun at birth and falls into the gate and line we expect.

The Human Design wheel divides the zodiac into 64 gates of 5.625 degrees each. Gate 41 begins at 2 degrees of Aquarius. Every gate has 6 lines of 0.9375 degrees, every line 6 colors, every color 6 tones. A tone is 93.75 arc seconds wide. That makes 13,824 positions on the wheel.

We check the wheel in three ways. If we sweep the whole circle in steps of 0.002 degrees, the position rises exactly 13,823 times, one step at a time, with no jump and no step backwards. At 200 points right on a tone boundary, the position a hair's breadth to the left and the position a hair's breadth to the right differ by exactly one. And the Sun enters gate 41 in late January: on 23 January in 2019 and 2026 it stands in that gate, on 20 January 2026 it does not yet.

From the 26 activations we collect all activated gates. A channel is active when both of its gates are activated. There are 36 channels, and they join the 9 centers. A center is defined when at least one complete channel touches it, otherwise it is open. We check that the channels drawn in the bodygraph are exactly the 36 channels of the calculation, none missing and none extra.

Type, authority, strategy and definition follow from which centers are defined and how the channels connect them. The profile is the line of the Personality Sun together with the line of the Design Sun. The Incarnation Cross is made of the gates of Sun and Earth in Personality and Design. The direction of the four arrows (the variables) follows the tone of the respective point: tones 1 to 3 point left, tones 4 to 6 point right.

Human Design is the system of Ra Uru Hu. We implement its rules as code, and every number named on this page is measured in a test.

The Sun needs between 5.5 and 5.9 days for one gate and about one day for one line. The Moon changes its line roughly every 1.5 to 1.9 hours and its tone every 2.4 to 3.2 minutes. That is why the exact birth time matters most for the Moon: a few minutes can change a tone, a couple of hours can change a line, while the Sun only moves on to the next gate after several days.

4 complete reference charts are stored with every value: a winter birth in Düsseldorf, a night birth in Sydney in the southern hemisphere, a birth in Mumbai in a half hour time zone and a summer birth in Berlin. If a single value changes, a test fails. A change to the calculation therefore never happens by accident, only on purpose.