As we know One J/mg is equal to 1000000 J/kg (1 J/mg = 1000000 J/kg).

To convert Joule/Milligram to Joule/Kilogram, multiply your J/mg figure by 1000000.

Example : convert 25 J/mg to J/kg:

25 J/mg = 25 × 1000000 J/kg = J/kg

To convert Joule/Kilogram to Joule/Milligram, divide your J/kg figure by 1000000.

Example : convert 25 J/kg to J/mg:

25 J/kg = 25 ÷ 1000000 J/mg = J/mg