Chemistry
Crude Protein Calculator
Convert a Kjeldahl nitrogen titration into the nitrogen and crude protein content of a sample.
Your inputs
Change any value to update the result instantly.
Crude protein
10.768 %
Nitrogen content
1.7229 %
Net titrant volume
12.3 mL
Conversion factor used
6.25
Protein in the sample
107.68 mg
Crude protein assumes all nitrogen comes from protein, so non-protein nitrogen inflates the figure. The conversion factor depends on the commodity, which is why it is selectable here.
What this calculator does
Converts a Kjeldahl titration into nitrogen percentage and crude protein using the appropriate conversion factor.
What your result means
The protein content of the sample as conventionally reported for food and feed.
Formula and working
%N = ((V_sample − V_blank) × N_acid × 14.007 × 100) / (m_sample × 1000); %protein = %N × factor
- 1
Collect the inputs
Titrant used for the sample = 12.5 mL; Titrant used for the blank = 0.2 mL; Acid normality = 0.1 N; Sample mass = 1 g; Protein conversion factor = 625
- 2
Apply the formula
%N = ((V_sample − V_blank) × N_acid × 14.007 × 100) / (m_sample × 1000); %protein = %N × factor
- 3
Result
Crude protein = 10.768 %
Frequently asked questions
Symbols and assumptions
- V
- Titrant volume
- N
- Acid normality
- 14.007
- Atomic mass of nitrogen
- factor
- Nitrogen-to-protein factor
- • Titration against a standardised acid with a blank correction.
- • The selected conversion factor suits the commodity.
Sources and review
Reviewed 2026-09-22 · Next review 2027-09-22
- • Crude protein assumes all nitrogen is protein nitrogen, so non-protein nitrogen inflates the result.
Important limitation
This is an educational estimate based only on the values and formula shown. Verify current rates, rules, units, and professional standards before relying on the result. It is not personalized financial or investment advice.
Report a mistake or request an improvement
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