Enter a kilocalorie rate (kcal/h, kcal/min, or kcal/s) or a power unit (W, kW, MW) to convert to the other value.

Kcal to kW Conversion Calculator

Use Energy over time when your kcal value is a total amount, not a rate.

Rate to kW
Energy over time
kW to kcal/h

Kcal to kW Formula

Kilocalories measure energy. Kilowatts measure power. To convert, you need either a kcal rate (kcal per unit time) or a total kcal divided by a time.

kW = (kcal/h × 4184) / (3600 × 1000)
kW ≈ kcal/h × 0.001163

For a total energy over a time period:

kW = (kcal × 4.184) / t(seconds)

Reverse direction:

kcal/h = kW × 860.42
  • kW — power in kilowatts
  • kcal — energy in kilocalories (thermochemical, 1 kcal = 4184 J)
  • kcal/h — energy rate in kilocalories per hour
  • t — elapsed time in seconds

The calculator uses 1 kcal = 4184 J. The "large calorie" used in nutrition is the same unit as the kcal used here. If your source uses the International Table calorie (4186.8 J), the result differs by about 0.07 percent.

Reference Tables

Common direct conversions between kcal/h and kW:

kcal/h kW W
1000.116116
5000.581581
1,0001.1631,163
2,5002.9072,907
5,0005.8155,815
10,00011.6311,630
25,00029.0729,075
100,000116.3116,300

Typical kcal/h ranges by application:

Source kcal/h kW
Resting adult70 to 900.08 to 0.10
Office worker, light activity100 to 1500.12 to 0.17
Cyclist, moderate500 to 7000.58 to 0.81
Small electric heater860 to 1,7201 to 2
Residential boiler17,000 to 26,00020 to 30
Commercial chiller85,000+100+

Example

A heater is rated at 3,000 kcal/h. Find the power in kW.

kW = 3,000 × 0.001163 = 3.49 kW

Cross-check using the energy form. In one hour, the heater delivers 3,000 kcal × 4184 J/kcal = 12,552,000 J. Dividing by 3,600 seconds gives 3,487 W, or 3.49 kW.

FAQ

Is kcal the same as Cal (food calorie)?
Yes. The "Calorie" on a nutrition label with a capital C equals one kilocalorie.

Why does kcal need a time to convert to kW?
A kilocalorie is energy. A kilowatt is energy per second. Without a time, the conversion is undefined. Use the Energy over time tab when you only have a total kcal value.

What is the quick mental conversion?
Multiply kcal/h by 0.00116 to get kW, or divide kcal/h by 860 to get kW.