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Crude Protein Calculator

Crude protein refers to a food's blend of pure protein and non-protein nitrogen.



Percentage of crude protein


  • B = Blank titre value
  • S = Titre value
  • N = Normality of NaOH
  • W = Sample weight

Defination / Uses

A mixture of true protein and non protein nitrogen in a food is called crude protein.

It indicates a feed's abilities to fulfil an animal's nutritional needs. The approximate amount of protein in foods that is obtained by dividing the determined nitrogen content by a factor (as 6.25 for many foods and 5.7 for wheat) derived from the average percentage of nitrogen in food proteins and that may contain an appreciable error if the nitrogen is derived from non sources of protein material or from a protein of unusual composition.

Crude protein is a type of protein that is used for energy and to help create tissue. The total protein content in a feedstuff may be calculated by multiplying the nitrogen figure by 100/16 or 6.25, which is based on a laboratory nitrogen analysis. This is based on the assumption that nitrogen is obtained from 16 percent nitrogen protein (AOAC, 1984). However, because some non-protein nitrogen (NPN) is included in most diets, the number obtained by multiplying N x 6.25 is referred to as crude rather than genuine protein. Amino acids are composed of protein. Use the upper given formula for manual calculations. No sign-up, registration OR captcha is required to use this tool.