Approximately, Nitrogen contributes to 16% of proteins 100 gm of protein contains 16 gm of nitrogen. So, 62.5 gm of protein will contain, 62.5 X 16/100 gm of nitrogen, i.e. 10 gm of nitrogen. Extra Edge: Formula for calculating the nitrogen balance of patients: Nitrogen balance = Nitrogen intake - Nitrogen loss = (Protein intake x 0.16) - (24-hour urinary urea nitrogen + 4) Why to add 4? 4 gm of nitrogen is lost through other sources.