Metabolisable energy converter: kcal/kg ⇄ MJ/kg ⇄ Mcal/kg
Convert feed metabolisable energy between kcal/kg, Mcal/kg and MJ/kg. Exact factor, formula, worked diet examples and links to species feed calculators.
Short answer · reviewed August 2026
To convert feed metabolisable energy from kcal/kg to MJ/kg, divide by 239.0057 (1 MJ = 239.0057 kcal, 1 kcal = 4.184 kJ). A broiler grower diet at 3,100 kcal/kg ME is 12.97 MJ/kg. Going the other way, multiply MJ/kg by 239.0057: 11.5 MJ/kg equals 2,749 kcal/kg.
Convert now
Equals
12.97 MJ/kg
= 3.1 Mcal/kg
Equals
2988 kcal/kg
1 MJ = 239.0057 kcal
Results are unit conversions only — always confirm the analytical basis stated on the supplier certificate of analysis.
Formula
MJ per kg = kcal per kg ÷ 239.0057 kcal per kg = MJ per kg × 239.0057 Mcal per kg = kcal per kg ÷ 1,000 1 kcal = 4.184 kJ (thermochemical calorie)
US and Asian specifications usually quote kcal/kg, while European specifications quote MJ/kg. Confirm which energy system is used — poultry ME(N), swine ME/NE and ruminant ME are not interchangeable.
Worked examples
| Input | Calculation | Result |
|---|---|---|
| Broiler grower, 3,100 kcal/kg ME | 3,100 ÷ 239.0057 | 12.97 MJ/kg |
| Layer diet, 2,750 kcal/kg ME | 2,750 ÷ 239.0057 | 11.51 MJ/kg |
| Swine grower, 13.4 MJ/kg ME | 13.4 × 239.0057 | 3,203 kcal/kg |
| Maize, 3,350 kcal/kg ME (poultry) | 3,350 ÷ 239.0057 ; ÷ 1,000 | 14.02 MJ/kg = 3.35 Mcal/kg |
FAQ
How many MJ is 3,000 kcal/kg of feed energy?
3,000 kcal/kg divided by 239.0057 gives 12.55 MJ/kg.
What is the exact kcal to MJ conversion factor?
One kilocalorie equals 4.184 kilojoules, so 1 MJ equals 239.0057 kcal. Divide kcal/kg by 239.0057 to get MJ/kg.
Is Mcal the same as Mcal ME?
Mcal is only a unit: 1 Mcal = 1,000 kcal. Whether the number is ME, DE or NE depends on the energy system stated in the specification.
Can I compare a poultry ME value with a swine NE value?
No. Net energy values are lower than metabolisable energy for the same ingredient, and poultry ME is corrected for nitrogen retention. Convert units first, then compare only within the same energy system.