Crude Protein Calculator

Calculate crude protein content using Kjeldahl method, nitrogen analysis, and protein conversion factors for food and feed analysis.

Enter Analysis Data

g
mL
mL
N

Results

Enter analysis data to calculate crude protein

Crude Protein Analysis

Kjeldahl Method

% Protein = % N × Conversion Factor

  • • Digestion with H₂SO₄
  • • Distillation of NH₃
  • • Titration with HCl
  • • Most common method

Conversion Factors

  • • General: 6.25
  • • Wheat: 5.7
  • • Dairy: 6.38
  • • Soy: 5.83
  • • Meat: 6.25

Protein Sources

Plant Sources

  • • Soybean meal: 45-50%
  • • Wheat flour: 10-15%
  • • Corn meal: 8-10%
  • • Rice bran: 12-15%

Animal Sources

  • • Meat meal: 50-60%
  • • Fish meal: 60-70%
  • • Milk powder: 25-35%
  • • Blood meal: 80-90%

Feed Ingredients

  • • Cottonseed meal: 40-45%
  • • Sunflower meal: 35-40%
  • • Peanut meal: 45-50%
  • • Canola meal: 35-40%

Applications

Food Industry

  • • Nutritional labeling
  • • Quality control
  • • Product development
  • • Regulatory compliance

Feed Industry

  • • Feed formulation
  • • Nutritional analysis
  • • Cost optimization
  • • Quality assurance