Sixteen portions, three starting signs
Shodashamsha, also spelled Shodasamsa and called Kalāṁśa, is the sixteenth divisional chart in Jyotish. A sidereal rāśi spans 30°. D16 divides it into sixteen equal 1°52′30″ portions. The first portion of a movable sign counts from Aries, of a fixed sign from Leo, and of a dual sign from Sagittarius. Each later portion moves one sign forward through the zodiac, wrapping after Pisces.
This calculator applies the rule stated in Bṛhat Parāśara Horā Śāstra 6.16 to this site's independent sidereal D1 positions. It uses Astronomy Engine 2.1.19, an approximate Lahiri ayanamsha, the seven classical grahas, and mean Rahu and Ketu. Enter the historical UTC offset yourself: a place name does not supply a time-zone history.
Reading the result
Each row preserves the observed D1 sidereal sign and degree, gives the numbered D16 portion, identifies its Aries, Leo, or Sagittarius starting sign, and shows the derived D16 sign and degree. The South Indian diagram fixes signs in place and marks the transformed Lagna. The deity column repeats a four-name sequence from the source verse: Brahma, Vishnu, Shiva, and Surya in odd D1 signs; reverse order in even D1 signs.
The D16 degree is an expanded mathematical coordinate, not an additional observed planetary longitude. For study, compare this derived chart with the D1 rāśi chart and the full D16 method guide. The calculator does not predict a purchase, accident, or travel outcome.