Enter the energy in kJ/kg and the mass flow rate in kg/s into the calculator to convert to power in kilowatts (kW).

kJ/kg ↔ kW Calculator

General (Energy · Flow · Power)
Fuel → kW

Fill any two fields — leave the third blank to solve for it.

Enter a fuel’s specific energy and its burn rate to estimate thermal power output.

Use 100% for heat output, ~30-40% for engines, ~55-60% for combined-cycle plants.
Power
—
▸ Show calculation
Recent calculations (click to reload)
kJ/kg ↔ kW Conversion Table (ṁ = 1 kg/s)
kJ/kg to kW kW to kJ/kg
14000 kJ/kg = 14000 kW50 kW = 50 kJ/kg
16000 kJ/kg = 16000 kW100 kW = 100 kJ/kg
18000 kJ/kg = 18000 kW250 kW = 250 kJ/kg
25000 kJ/kg = 25000 kW500 kW = 500 kJ/kg
30000 kJ/kg = 30000 kW1000 kW = 1000 kJ/kg
42000 kJ/kg = 42000 kW1500 kW = 1500 kJ/kg
45000 kJ/kg = 45000 kW2000 kW = 2000 kJ/kg
46000 kJ/kg = 46000 kW5000 kW = 5000 kJ/kg
48000 kJ/kg = 48000 kW10000 kW = 10000 kJ/kg
50000 kJ/kg = 50000 kW20000 kW = 20000 kJ/kg
Formula: P(kW) = E(kJ/kg) × ṁ(kg/s). Here ṁ = 1 kg/s.
kJ/kg ↔ kW Conversion Table (ṁ = 0.1 kg/s)
kJ/kg to kW kW to kJ/kg
15000 kJ/kg = 1500 kW100 kW = 1000 kJ/kg
20000 kJ/kg = 2000 kW250 kW = 2500 kJ/kg
24000 kJ/kg = 2400 kW500 kW = 5000 kJ/kg
28000 kJ/kg = 2800 kW750 kW = 7500 kJ/kg
32000 kJ/kg = 3200 kW1000 kW = 10000 kJ/kg
35000 kJ/kg = 3500 kW1500 kW = 15000 kJ/kg
40000 kJ/kg = 4000 kW2000 kW = 20000 kJ/kg
43000 kJ/kg = 4300 kW3000 kW = 30000 kJ/kg
47000 kJ/kg = 4700 kW4000 kW = 40000 kJ/kg
52000 kJ/kg = 5200 kW5000 kW = 50000 kJ/kg
Formula: P(kW) = E(kJ/kg) × ṁ(kg/s). Here ṁ = 0.1 kg/s.

kJ/kg to kW Conversion Formula

The following formula is used to convert specific energy in kJ/kg to power in kW.

P (kW) = E (kJ/kg) * ṁ (kg/s)

Variables:

  • P is the power in kilowatts (kW)
  • E is the specific energy in kilojoules per kilogram (kJ/kg)
  • ṁ is the mass flow rate in kilograms per second (kg/s)

To convert energy in kJ/kg to power in kW, multiply the energy value by the mass flow rate. (Because kJ/kg × kg/s = kJ/s, and 1 kW = 1 kJ/s.)

What is Energy to Power Conversion?

Energy to power conversion is the process of converting a specific amount of energy per unit mass (kJ/kg) to power (kW) using the mass flow rate. This conversion is particularly useful in engineering fields such as thermodynamics and mechanical engineering, where it is important to understand the power output of a system based on the energy content of the fuel or working fluid and the rate at which it is being consumed or processed.

How to Calculate Power from Energy and Mass Flow Rate?

The following steps outline how to calculate power from energy and mass flow rate.

  1. First, determine the energy content per unit mass (E) in kJ/kg.
  2. Next, determine the mass flow rate (ṁ) in kg/s.
  3. Use the formula P (kW) = E (kJ/kg) * ṁ (kg/s) to calculate the power.
  4. Finally, enter the values into the calculator above to verify the result.

Example Problem:

Use the following variables as an example problem to test your knowledge.

Energy content per unit mass (E) = 500 kJ/kg

Mass flow rate (ṁ) = 2 kg/s