Imum Coeli (IC) Calculator
Your Imum Coeli, or IC, is the lowest point of your chart and the cusp of the fourth house. It describes your roots, your home, your family of origin, and the private self you return to. Opposite the Midheaven, it needs an exact birth time.
Frequently asked questions
What is the Imum Coeli (IC)?
The Imum Coeli, or IC, is the point at the very bottom of your chart — the cusp of the fourth house and the lowest angle. It represents your roots, home, family of origin, ancestry, and the most private foundation of who you are.
How is the IC calculated?
The IC always sits exactly 180° from your Midheaven, in the opposite sign. We find your Midheaven from your exact birth time and place, then place the IC directly across the chart from it, so the two form a perfect vertical axis.
Why does the IC need an exact birth time?
Because it is anchored to the Midheaven, which shifts continuously and changes sign roughly every two hours, an accurate birth time is essential. Without it, the wrong IC sign can be calculated.