kJ/kg to kW Calculator

Convert specific energy (kJ/kg) to power (kW) using mass flow rate. Essential for thermodynamics, HVAC systems, and power plant calculations.

Thermodynamics Calculator:

Calculate power output from specific energy and mass flow rate. Used in steam turbine analysis, boiler efficiency, and industrial heat transfer.

kJ/kg to kW Converter

Mode

Energy per unit mass

Mass flow per unit time

Calculation Results

Enter specific energy and mass flow rate

then click "Calculate" for power

kJ/kg to kW Calculator

In thermodynamics and engineering, kJ/kg represents specific energy — how much energy exists per kilogram of substance. kW represents power, which is energy transferred per second. To convert between them, you need one crucial piece of information: the mass flow rate.

The Formula

The relationship is straightforward once you understand the units:

Basic Formula
kW = (kJ/kg) × (Mass Flow Rate in kg/s)

If your mass flow rate is in kg/hour, divide by 3600 to convert to kg/s:

Formula for kg/hr
kW = (kJ/kg × kg/hr) ÷ 3600

Example Calculation

Given:
Specific Energy = 500 kJ/kg
Mass Flow Rate = 2 kg/s

Calculation:
kW = 500 × 2 = 1000 kW

kJ/kg to kW Conversion Table

The table below shows various conversions:

kJ/kg Mass Flow (kg/s) Result (kW)
100 1 100 kW
200 1 200 kW
300 2 600 kW
400 1.5 600 kW
500 2 1000 kW
600 3 1800 kW
750 0.5 375 kW
800 2.5 2000 kW
900 4 3600 kW
1000 3 3000 kW
1200 2 2400 kW
1500 1 1500 kW
1800 0.8 1440 kW
2000 2 4000 kW
2500 1.5 3750 kW
3000 0.5 1500 kW
3500 2 7000 kW
4000 1 4000 kW
4500 3 13500 kW
5000 4 20000 kW
6000 2.5 15000 kW
Pro Tip:

Remember that specific energy alone doesn't tell you the power output. Power depends on how much mass flows per second. A system with high specific energy but low flow rate can produce less power than one with lower specific energy but higher flow rate.