CFL Light Bulb Power Consumption Calculator

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CFL Light Bulb power consumption

CFL light bulb power consumption is less than the incandescent bulb but more than new energy efficient LED’s. Using the below calculator you can calculate power consumption of a CFL bulb.

On an average to produce the same lumens a  CFL light bulb consumes 1.5 to 2 times more power than a LED light bulb. A 10 watt CFL light bulb running for 10 hours in a day will consume 100 watt hours in a day and 3 kWh of electricity in a month.

The job of any light source is to produce high intensity bright light. Intensity of brightness offered by light is measured in Lumens.

A  CFL bulb and LED bulb might have the same lumens (intensity of light) output, but the amount of energy consumed to generate that level of brightness will vary significantly in both cases.

The table below shows lumens (light intensity) and corresponding power consumption of CFL, LED & incandescent bulb to produce same value of lumens.

CFL Vs LED Vs Incandescent Light:

Lumens LED (Watt) CFL (Watt) Incandescent (Watt)
400 - 500
6 - 7
8 - 12
650 - 800
7 - 10
13 - 18
1000 - 1400
11 - 13
18 - 23
1600 - 1800
16 - 20
23 - 30
2700 +
25 - 28
30 - 55

From the above table one can deduce that a CFL bulb requires 1.5 to 2 times more wattage to produce same amount of lumens than a LED.

Hence power consumption of a CFL is 1.5 to 2 times of LED.

To use the CFL light power consumption calculator to calculate the power consumption of your CFL bulb and interpret the results correctly you should understand the following terms.

If you know these terms then feel free to scroll down to use the CFL light power consumption calculator.

  • What is Watt (W) – Watt is the unit of power. It means the rate at which electricity is consumed or produced by a device. For example a 10 watt light bulb consumes power at a rate of 10 watts per hour, it does not mean that the light bulb consumed 10 units of electricity, it means it will consume power at a rate of 10 watts every hour.
  • What is Kilowatt (kW) – Kilowatt is also a unit of power. Kilowatt (KW) is used for large devices that consume more power. For example a 1.5 kW air conditioner, 6 kW elevator. (1 kW = 1000 W)
  • What is a Kilowatt hour (kWh) – Units as described in electricity bill a.k.a kilowatt hour is the energy consumption of a device. For example a 20 watt LED bulb running for 50 hours will consume 20 watt x 50 hours = 1000 watt hours = 1 kilowatt hour of electricity = 1 unit of electricity. (1 kWh of electricity = 1 unit of electricity)
  • Electricity Tariff – Electricity tariff is the amount the electricity provider charges you for one unit (kWh) of electricity. I live in Mumbai, India here the electricity tariff is Rs 12/kWh. If you don’t know how to calculate your tariff then just divide your total bill by monthly power consumption and you will get your electricity tariff.
  • What is operational hours – Operational hours of a device refers to how many hours the device is working. If you run your television for 3 hours then operational hours of your television is 3 hours.

To calculate the power consumption of your Light bulb be it CFL, LED or any other type just put the wattage, operational hours and electricity tariff in the below calculator and you will get the power consumption of your LED light and the electricity bill you will get for using it.

You can use the above chart to find out your LED wattage or go to amazon and search for your LED and read the product description.

CFL Light Bulb Power Consumption Calculator:

CFL VS LED Bulb Power Consumption:

Here I have taken a 18 watt CFL which prodcues 1000 lumens and compared it with a 12 watt LED which also produces 1000 lumens to give you a rough estimate on power consumption of LED & CFL.

To produce 1000 lumens a CFL requires 18 watts whereas a LED requires just 12 watts.

For the below calculation I have assumed the electricity tariff is Rs 10.

Wattage For 1100 Lumens (W)
18 watt
12 watt
Life in hours
6,000 hours
15,000 hours
Price (Rs)
Rs 150
Rs 185
Power Consumed in 8 hours operation (Watt X 8) (P8)
Monthly Power Consumption (P8 X 30) (M)
4.32 kWh
2.88 kWh
Monthly Electricity Bill (Rs) (M X 10)
Rs 43
Rs 29
Annual Power Consumption (P8 X 12) (A)
51.84 kWh
34.56 kWh
Yearly Electricity Bill (Rs) (A X 10)
Rs 518
Rs 345

As you can see from the above table the annual power consumption of a 18 watt CFL which gives 1000 lumens intensity is 51.84 kWh whereas a 10 Watt LED which gives same 1000 lumens only consumes 34.56 kWh of electricity.

The difference in price isn’t much either, In today’s time it is best you opt for a LED light because they aren’t much expensive when compared to CFL’s and there power consumption is very low.

Final Opinion On CFL Light Bulb:

Even though CFL light bulb is less energy efficient they are not all bad. I feel is you have a room where light is ON for very less time (e.g., Store room, Terrace) than you can use a CFL to light that place.

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Thank You for reading 🙂

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