Tube feeding calculator (enteral rate, calories, protein, free water)
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Result
For exam practice only. This is a study aid, never a clinical decision: always follow the prescription, local protocols and the product information.
Plan or check an enteral (tube) feeding regimen. Enter the energy density, protein and free water content of the formula from its label; then calculate the continuous pump rate for a calorie goal, the calories and protein a given rate delivers, or the volume per bolus feed. Water flushes are added to the free water, and an optional weight gives kcal/kg and g protein/kg.
Step-by-step solution
Volume per day = calorie goal ÷ energy density
Pump rate = volume ÷ feeding hours
What the formula delivers
Total free water
Per kg body weight
Key formulas
- Daily volume
- mL = kcal / (kcal/mL)
- Continuous feed
- mL/h = daily volume / hours of feeding
- Bolus feed
- mL per feed = daily volume / number of feeds
- Energy and protein delivered
- kcal = mL × kcal/mL; g = L × g/L
- Free water
- mL = formula volume × water fraction
How to calculate a tube feeding rate
- Volume per day = calorie goal ÷ energy density: 1800 kcal ÷ 1.5 kcal/mL = 1200 mL.
- Continuous rate = volume ÷ feeding hours: 1200 mL ÷ 24 h = 50 mL/h. For cyclic feeding over fewer hours, the rate is higher.
- Protein = volume × protein per litre: 1.2 L × 60 g/L = 72 g/day.
- Free water = volume × water percentage of the formula, plus the water flushes: 1200 × 76% + 6 × 30 mL = 1092 mL.
- For bolus feeds, divide the daily volume by the number of feeds.
Questions and answers
What is free water in a tube feeding?
The water in the formula that is available to the body. Standard 1 kcal/mL formulas are about 84% water, concentrated 1.5 to 2 kcal/mL formulas about 70–78%. The label gives the exact value.
How do I find the protein content?
Formula labels give protein in g per 1000 mL (g/L) or per 100 mL; multiply a value per 100 mL by 10 to get g/L.
Why are water flushes counted?
Flushes before and after feeds and medicines can add several hundred millilitres of water a day, which matters for the total fluid intake.
How are calorie and protein goals set?
By the dietitian and the prescriber. Exam questions give the goal, often as kcal/kg/day (for example 25–30) and g protein/kg/day.
Practise it yourself
Practise Enteral & parenteral nutrition calculations
A calculator gives the answer. In the exam you need the method: practise it with new problems, hints and worked solutions.