This chart is seen for children and grandchildren, their possibility, well-being etc. Each sign of 30º is divided into 7 parts of 4º17΄8.57˝ each.
In odd signs counting stars from itself whereas in even signs counting starts from 7th from the sign where planet or lagna falls.
It is also believed that with regard to progeny better results are obtained from female charts than from male charts.
The 5th lord of D1, Jupiter, Beeja Sphuta & Kshetra Sphuta are to be verified mainly in D3.
It is the most important divisional chart and rightly considered to be the supplementary birth chart. Normally predictions are not ventured without Navamsha chart. It reveals inter alia the strength or weakness of the planet and the periods of stresses or strains in life. This chart is basically seen for married life, partner, temperament, disposition, character of the spouse, happiness and miseries in married life etc.
In this chart each sign of 30º is divided into 9 parts of 3º20΄ each. There are 27 nakshatras each having 4 parts or padas. Dividing 360º with 108 we get each nakshatra pada to have a longitude of 3º20΄ each which coincides with each navamsha division of 3º20΄. This explains the importance of navamsha and its justified use as a supplementary birth chart. There are various methods of constructing a navamsha chart
Method No 1:
For a planet/lagna posited in a fiery sign counting starts from Aries,
In earthy sign counting starts from Capricorn,
In airy sign counting starts from Libra and
In watery sign counting starts from Cancer.
Method No 2:
For a planet/lagna posited in a movable sign counting starts from the sign itself , in fixed sign counting starts from 9th and in dual sign starts counting starts from 5th from where the planet in posited.
Method No 3:
This is a mathematical method of calculating the navamsha chart. Multiply completed signs by 9 and add running Navamsha division to it. Divide the resultant figure by twelve. The reminder gives the sign where the planet will be posited in the navamsha chart. Assume Moon in Cancer in the birth chart at 22º12΄ in the 7th navamsha division. The completed signs are three and moon is in 4th sign. Multiply 3 by 9 giving 27 add 7 (the running navamsha division) to it giving 34. Divide this by 12 giving 10 as the reminder. Moon will be place in Capricorn (the 10th sign of the zodiac) in Navamsha.
Planets in the first Navamsha division in moveable sign, 5th division in fixed sign and 9th division in dual signs are Vargottama which means occupying the same sign in the birth chart as well as Navamsha chart.