What is a Navamsha chart?
A Navamsha chart is a derived chart: each rashi is split into nine equal parts, and every position is re-sorted by the part it falls in.
STEP 1
Nine slices per sign
Each 30-degree rashi is divided into nine navamshas of 3°20′ each, which makes 108 across the twelve signs. The translator points out that the 27 nakshatras, each split into four quarters, also make 108. So one navamsha lines up with one nakshatra quarter (pada).
STEP 2
Where the counting starts
Navamshas take the names of the twelve rashis, counted in order again and again from the start of Mesha. As a result, Mesha, Simha and Dhanus all begin with the Mesha navamsha. Vrishabha, Kanya and Makara begin with Makara. Mithuna, Tula and Kumbha begin with Tula. Kataka, Vrischika and Meena begin with Kataka.
STEP 3
A worked example
Take a point at 5° Vrishabha. Its first slice (0° to 3°20′) is Makara, and its second slice (3°20′ to 6°40′) is Kumbha. So in the Navamsha chart, which modern software often labels D9, this point is placed in Kumbha. Nothing new was observed in the sky. The same position was simply sorted a different way.
STEP 4
Work one out yourself
Choose a degree from a chart you already have and find its navamsha by hand. Each slice is only 3°20′ wide, so a small error in the recorded degree, such as one caused by an uncertain birth time, can push the result into the next sign. Be cautious with points near a boundary.
This explains the traditional chart calculation, not a verified prediction of marriage. Astro Aunty’s free Gun Milan calculates a Moon-based score out of 36; it does not generate a Navamsha, Lagna, or complete birth chart.