Which Human Design Chart calculation Method should I use – Tropical, Sidereal, or True Sidereal?

Last Updated: Jun 12, 2025

Tropical Human Design (Standard):

• Based on seasons, not the actual sky
• Uses the same 12 zodiac signs with equal sizes
• Spring equinox = Aries start, regardless of where stars actually are
• The system Ra Uru Hu originally used

Sidereal Fagan-Bradley:

• Looks at the real stars in the sky
• Accounts for Earth’s slow “wobble” (1° every 72 years)
• Still 12 equal zodiac signs, but about 24° “shifted back”
• Your Sun might “move” from Taurus to Aries

True Sidereal (Midpoint):

• Uses the actual sky like a planetarium
• Has 13 zodiac signs (including Ophiuchus, the Serpent Bearer)
• Each sign has its real size – Virgo is huge, Cancer is tiny
• Shows you where planets actually were when you were born

Practically this means: You could have different Types, Profiles, or Authorities in all three systems! Some people find that a different system resonates better with them.

Which is “correct”? All work – they’re different “lenses” through which you can view yourself.