astrootldr

Dominant planet calculator

Which element, modality, and planet carry the most weight in a chart. Enter birth date, time, and place; the calculator scores every placement by a fixed, published weighting and ranks the totals. Birth data stays in your browser.

Birth data

Your birth data stays in your browser. Nothing is sent to the server.

Advanced — manual coordinates & offset

Enter birth data above to compute element, modality, and planet dominance.

How the weighting works

There is no single canonical formula for chart dominants in astrology — different schools weight bodies differently. This calculator uses one fixed, transparent scheme so the numbers are reproducible:

  • Each planet contributes by tier: Sun and Moon = 3, Mercury, Venus, Mars, Jupiter, Saturn = 2, Uranus, Neptune, Pluto = 1.
  • The Ascendant adds 3 and the Midheaven adds 2 to element and modality totals (the angles carry no planet score).
  • For planet dominance, a body in an angular house (1, 4, 7, 10) gains +2, and each aspect it makes adds +0.5.

Element and modality totals come only from where each weighted body falls by sign. Percentages are each category's share of the total. This is a structural summary of the chart, not a personality reading. See methodology for the broader approach.

This is cultural and astronomical reference, not personal prediction or advice.

Dominants are a structural tally of a chart under one fixed weighting; other valid weightings give other results. Astrology is documented cultural material, not a scientifically demonstrated method of prediction. See the disclaimer.

Last reviewed .