Planetary Midpoints
A midpoint is the half-sum of two ecliptic longitudes — the exact arc between two planets. The Sun/Moon midpoint is the inner marriage of will and feeling; the Mars/Venus midpoint is appetite given a body. When a third planet falls on a midpoint by aspect, the pair’s theme fuses with that planet’s nature. This tool computes the full table.
The half-sum formula
For any two planets A and B, the midpoint is (longitude_A + longitude_B) / 2, normalised into 0–360°. Every midpoint has a near and a far half — the same axis crossed at the opposite point. The tool reports the closer of the two and lists every natal aspect to it within tight orbs (1° for hard, 1.5° for soft contacts).
Why midpoints reveal fused themes
A planet alone has a voice; two planets in aspect have a conversation; a third planet on their midpoint stands inside the conversation as the medium that carries it. Cosmobiology — Reinhold Ebertin’s school — built an entire reading practice on this. The text on this site keeps that precision while staying state-language: what fuses, not what occurs.
Reading the table
Start with the personal midpoints — Sun/Moon, Sun/Asc, Moon/Asc, Mars/Venus. These describe the integration most felt in daily life. Note which natal planets aspect them. A Saturn on Sun/Moon midpoint slows the inner marriage with weight and discipline; a Jupiter on Mars/Venus widens appetite into generosity. Outer-pair midpoints (Saturn/Pluto, Jupiter/Uranus) describe collective pressure your chart catches.
Where midpoints sit beside everything else
Midpoints are a precision layer on top of an already-read chart. They will not replace the natal interpretation. They are most useful when the basic chart leaves a question — why this planet acts so differently than its sign would suggest, why two themes feel inseparable. Read alongside /astrology and the major-aspect table.
Frequently Asked Questions
How many midpoints does the chart have?
For ten planets it is 45 unique pairs; with the four angles included it expands further. The tool ranks them by the number of natal aspects, so the most active midpoints rise to the top.
Which orbs are used?
Midpoint orbs are tight: 1° for conjunction, square and opposition; 1.5° for trine and sextile; 30 arc-minutes for the semi-square family. Wider orbs dilute the fused theme into ordinary aspect noise.
Are direct and indirect midpoints both valid?
Both axes are valid. Cosmobiology often works with both halves on a 90° dial; the table here lists the closer half so the reading stays grounded in the visible chart, with the opposite half implied.