Nitrogen Balance calculator
Result
-4.4g N/day
Mild catabolism
+4 gN/4 constant for insensible losses (stool, skin, fistulae adds).
How to use it
- 1
24h urine urea nitrogen. Collect accurately; creatinine clearance from same sample validates collection.
- 2
N balance = (protein g / 6.25) − (UUN + 4). 4 = constant for stool and insensible N losses.
- 3
Target +2 to +4 g N/day. In anabolic phase. Critically ill: target 0 to +2 g/day (prevent catabolism).
When to use it
- ICU protein optimisation
- N balance guides protein delivery (1.2–2 g/kg/day target in critical illness).
- Post-operative nutrition
- Confirms adequacy of protein intake during recovery.
- Burns and trauma
- Severe catabolism common — N balance guides daily adjustment of enteral/parenteral feeds.
A reference for clinicians and students, not medical advice. A score supports a decision; it does not make one. Check every result against the patient in front of you and your local protocol.
At a glance
- Specialty
- Nutrition
- Inputs
- 2
- Type
- Formula
More in nutrition
- Harris-Benedict BMRNutrition · 4 inputs
- Mifflin-St Jeor BMRNutrition · 4 inputs
- MUST ScoreNutrition · 3 inputs
- NRS-2002Nutrition · 7 inputs
- Body Mass Index (BMI)Endocrinology and metabolism · 2 inputs
- Corrected CalciumEndocrinology and metabolism · 2 inputs
- Corrected Sodium (Hyperglycaemia)Endocrinology and metabolism · 2 inputs
- HbA1c ↔ eAGEndocrinology and metabolism · 1 input
- HOMA-IREndocrinology and metabolism · 2 inputs
- Body Surface Area (Mosteller)Endocrinology and metabolism · 2 inputs
- Ideal Body Weight (IBW)Endocrinology and metabolism · 2 inputs
- Waist-Hip RatioEndocrinology and metabolism · 3 inputs
