kalas

Sandipani Muni imparted this knowledge to Sri Krishna.

In the scriptures, Chaitanya-Shakti is measured by means of kalas.

According to this:

1. Rocks, minerals and other inert matter have the lowest Chaitanya-Shakti of 1 kala.
2. Plants are the next evolution of Chaitanya-Shakti with 2 kalas.
3. Animals have 3,4 kalas.
4. Average human beings have 5 kalas.
5. Human beings with higher spiritual capacities have 6 kalas.
6. Saints have 7 kalas. 
7. The most advanced saints and sages have 8 kalas. It is not possible for saints to go beyond 8 kalas. A normal human body cannot sustain greater than 8 kalas. 

Beyond that starts the incarnations (avataras) with special sattva bodies.

1. Varaha Avatara of Vishnu had special sattva body with 11 kalas.
2. Sri Ramachandra incarnated with 12 kalas.
3. When Sandipani Muni was imparting this knowledge to Sri Krishna and Balarama, he did not know that Sri Krishna was an Avatara. He mentioned upto Sri Ramachandra and said that in future other Avataras of Vishnu will incarnate. Sri Krisha incarnated with 16 kalas (Purna-Avatara), the highest possible Chaitanya Shakti. Amsa-Avataras incarnate with lesser kalas

Goddess Uma is also said to have 16 kalas. This is said in Sri Lalita 483:

Om amrtaadi maha sakti samvrtaayai namah: Salutations to Her who is surrounded by sixteen Saktis beginning with Amrta.

As Siva, he is concorporate with Uma.So he is also said to have 16 kalas.

https://www.speakingtree.in/blog/16-kalas-of-shri-krishna
https://www.quora.com/If-Lord-Vishnu-has-16-kalas-how-many-kalas-does-Lord-Shiva-have