Karana explained: the half tithi
A karana is half a tithi, the time the Moon takes to move 6 degrees farther from the Sun. There are 11 karanas in use, in a repeating pattern across the lunar month.
What it is
Seven movable karanas repeat eight times, and four fixed karanas occur once each in the month. The fixed ones are Shakuni, Chatushpada, Naga and Kimstughna. Their names and order are given in the classical texts.
How it is worked out or read
The karana index is the integer part of the Moon's elongation divided by 6 degrees. Index 0 is Kimstughna, indices 1 to 56 cycle through the seven movable karanas, and 57 to 59 are the three last fixed karanas.
Where it appears on this site
The karana appears in the panchang. Karanas are less used in practice than tithi or nakshatra, and this site states the rule and nothing more.
The eleven karanas in order
Seven movable karanas repeat in a cycle of eight across the lunar month, giving fifty-six positions. Four fixed karanas occupy the last few positions of the month. The movable karanas have traditional names such as Bava, Balava, Kaulava, Taitila, Gara, Vanija and Vishti. Vishti is the one most often mentioned as inauspicious. The fixed karanas are Shakuni, Chatushpada, Naga and Kimstughna. Because the order is fixed, a reader who knows the position in the month can name the karana without a table.
Why karanas are used less
In practice karanas are rarely the deciding factor in a choice. Most traditions consider the tithi, the nakshatra and the weekday first, and treat the karana as a refinement. Some almanacs print it prominently, and some omit it. This site shows the karana in the panchang for completeness. A reader should not give it more weight than the sources do, and should note whether the rule being followed uses karanas at all.
Karana and the timing of an event
If a karana matters for a particular activity, the tradition usually asks for it at the start of the activity, not for the whole day. The panchang gives the karana at sunrise and the time it changes. A reader who uses karanas should therefore check the time of the activity against the change time, rather than relying on the karana for the day as a whole. This is one more reason to read the panchang as a timed sequence rather than as a single entry per date.
Karana and the rhythm of the lunar month
The karana sequence repeats in a pattern across the lunar month, and a reader who looks at the karana alongside the tithi can see how the two rhythms relate. The tithi counts the Moon's phase in twelve-degree steps, and the karana counts it in six-degree steps, so each tithi contains exactly two karanas.
Karana in the lunar month
The karana cycle covers the full lunar month, so a reader who follows it over several months will see the same karanas return in the same order. This regularity is one of the features that makes the karana a precise and checkable element of the panchang.