A common conversion factor of 6.25 has been used worldwide to estimate crude protein content. However, many researchers especially Jones (1931) has extensively researched and did not agree with using the same factor for every food ingredient as it resulted in misleading estimation of crude protein content. ICMR/NIN and FAO/WHO/UNU recommendations over decades for protein and amino acid requirements using various techniques are used to state Estimated Average Requirement (EAR) and Recommended Daily Allowance (RDA) as accurate as possible. In the present manuscript, nitrogen: protein conversion factor has been reworked using NDpCal%.