Question

what is formula of milk

Answer 1

There is no chemical formula for milk. Milk is a mixture of different substances.

Milk composition varies depending on the species (cow, goat, sheep), breed (Holstein, Jersey), the animal's feed, and the stage of lactation.

Answer 2

Milk does not have a formula as it is a combination of different substances which is composed of several proteins, one main carbohydrate, fats/lipids, etc. Unless you were looking for the chemical bonds of milk, a clear answer cannot be provided.