Nitrogen Balance (nutrition support)
Nitrogen balance for nutrition support: (24-h protein intake ÷ 6.25) − (24-h urine urea nitrogen + insensible losses).
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- 24-hour protein intake
- 100 g
- 24-hour urine urea nitrogen
- 8 g
Result: Nitrogen balance +4 g/day — anabolic.
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Interpretation
- Positive = anabolic (intake exceeds losses), negative = catabolic. Needs a complete 24-h urine; unreliable in renal impairment.
What you enter
- 24-hour protein intake
- 24-hour urine urea nitrogen
- Insensible losses (default 4)
How this is calculated
- Formula
- N balance (g/day) = (protein g ÷ 6.25) − (24-h UUN g + insensible losses, default 4). 6.25 g protein carries 1 g nitrogen.
American Society for Parenteral and Enteral Nutrition (ASPEN) nutrition-support core curriculum: nitrogen balance = (protein intake ÷ 6.25) − (urine urea nitrogen + insensible losses). Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.