The sign and its names
Karka means a crab, and the sign is drawn as a crab with raised claws. Cancer is Latin for the same animal. It is the fourth sign. In Devanagari the Sanskrit name is written कर्क.
Element, quality and ruler
Cancer is a water sign and a movable sign. The four elements each hold three signs 120 degrees apart, and Cancer shares water with Scorpio and Pisces. The water signs are the fourth, eighth and twelfth of the twelve. The three qualities repeat around the circle, and Cancer shares movable with Aries, Libra and Capricorn. The movable signs open each run of three: the first, fourth, seventh and tenth. These are traditional labels for sorting the signs.
The ruling planet of Cancer is Moon. Cancer is the only sign Moon rules. The Moon goes round the Earth in about 27.3 days relative to the stars. It is the only ruler that moves fast enough to change sign every two or three days, and it rules only this one sign.
The nakshatras in Cancer
Cancer covers sidereal longitude 90 to 120 degrees, which is exactly nine padas, or two and a quarter nakshatras. The nakshatras with a part inside it are: Punarvasu (pada 4 only); Pushya (all four padas); Ashlesha (all four padas). Their ruling planets are Jupiter, Saturn and Mercury. Cancer is the only sign ruled by the Moon. It contains the star group Pushya and the faint Beehive cluster. Its opposite sign is Capricorn.
The Moon takes about two to two and a half days to cross a sign, so a moon sign of Cancer lasts that long each month. The nakshatra the Moon is in narrows it down further. Use the nakshatra finder to see both for your birth.
Moon sign Cancer and Sun sign Cancer
Your Vedic moon sign, the rashi, is the sidereal sign the Moon was in at birth. Your Western sun sign is the tropical sign the Sun was in. They are different measures, and the sidereal zodiac sits about 24 degrees 13 minutes behind the tropical one in 2026.
For Cancer the dates show it. In 2026 the Sun is in sidereal Cancer from 16 July 2026 to 17 August 2026, and in the Western Cancer from 21 June 2026 to 23 July 2026. Only about 7 days of those two ranges overlap, so most people with a Western sun sign of Cancer have a Vedic sun sign in Gemini, and a moon sign in any of the twelve. The moon sign changes every couple of days, so the moon sign calculator asks for your birth time and place.
The padas of Cancer and the navamsha
The nine padas inside Cancer take nine navamsha signs in a row. They start at Cancer and run on to Pisces, then the next sign, Leo, starts again at Aries. That is how a single degree of the moon sign points to a second sign in the D9 chart, which is read for finer detail.
Counting from Cancer
Vedic readers often count planets by their distance in signs from the moon sign, called the position from the Moon. With a moon sign of Cancer, the count runs: Leo is second, Virgo is third, Libra is fourth, Scorpio is fifth, Sagittarius is sixth, Capricorn is seventh, Aquarius is eighth, Pisces is ninth, Aries is tenth, Taurus is eleventh, Gemini is twelfth. The sign opposite Cancer is Capricorn, and the two signs in a trine with it are Scorpio and Pisces.
Sun in Cancer: Karka Sankranti
The Sun enters Karka in mid July. It starts the Tamil month Aadi and the Malayalam month Karkidakam, and is traditionally counted as the start of Dakshinayana, the Sun's southward half of the year.
Calculated with the Lahiri ayanamsa and whole sign houses; every setting is on the method page. Last checked 2026-10-04.